{"id":467,"date":"2023-01-23T16:37:08","date_gmt":"2023-01-23T07:37:08","guid":{"rendered":"https:\/\/dozzing.kr\/wordpress\/?p=467"},"modified":"2025-10-24T11:49:20","modified_gmt":"2025-10-24T02:49:20","slug":"javascript-%ec%9e%90%eb%b0%94%ec%8a%a4%ed%81%ac%eb%a6%bd%ed%8a%b8-%ec%9e%85%eb%ac%b8","status":"publish","type":"post","link":"https:\/\/blog.dozzing.kr\/?p=467","title":{"rendered":"[JavaScript] \uc790\ubc14\uc2a4\ud06c\ub9bd\ud2b8 \uc785\ubb38"},"content":{"rendered":"<p><dodo>\ud83d\udc33<strong><yy><a class=\"wp-editor-md-post-content-link\" href=\"https:\/\/learnjs.vlpt.us\/\">\ubca8\ub85c\ud37c\ud2b8\uc640 \ud568\uaed8\ud558\ub294 \ubaa8\ub358 \uc790\ubc14\uc2a4\ud06c\ub9bd\ud2b8<\/a><\/yy><\/strong>\ub97c \ubcf4\uba74\uc11c \uc815\ub9ac\ud55c \uae00 \uc785\ub2c8\ub2e4 \ud83d\udc33<\/dodo><\/p>\n<h2>1. Hello JavaScript<\/h2>\n<ul>\n<li>\ud06c\ub86c \uac1c\ubc1c\uc790 \ub3c4\uad6c\uc5d0\uc11c Console\ud0ed\uc744 \uc5f4\uace0 \ucf54\ub4dc \uc785\ub825\ud558\uae30<\/li>\n<\/ul>\n<h3>1) Hello JavaScript \ucd9c\ub825\ud558\uae30<\/h3>\n<p><code>console.log('Hello JavaScript!');<\/code><br \/>\n- \uacb0\uacfc\uac12 : <code>Hello JavaScript!<\/code><br \/>\n\u00a0<\/p>\n<h3>2) \uc5f0\uc0b0<\/h3>\n<p><code>console.log(1 + 2 + 3 + 4);<\/code><br \/>\n- \uacb0\uacfc\uac12 : <code>10<\/code><\/p>\n<p>\u00a0<\/p>\n<h2>2. \ubcc0\uc218\uc640 \uc0c1\uc218<\/h2>\n<h3>1) \ubcc0\uc218<\/h3>\n<ul>\n<li>\ubcc0\uc218\ub294 \ubc14\ub014 \uc218 \uc788\ub294 \uac12<\/li>\n<li>\ubcc0\uc218 \uc120\uc5b8 \ud560 \ub54c\uc5d0\ub294 <code>let<\/code> \ud0a4\uc6cc\ub4dc \uc0ac\uc6a9<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">let value = 1;\nconsole.log(value);\n<\/code><\/pre>\n<ul>\n<li>\uacb0\uacfc\uac12 : <code>1<\/code><br \/>\n\u00a0<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">let value = 1;\nconsole.log(value);\nvalue = 2;\nconsole.log(value);\n<\/code><\/pre>\n<ul>\n<li>\uacb0\uacfc\uac12<br \/>\n<code>1<\/code><br \/>\n<code>2<\/code><br \/>\n\u00a0<\/li>\n<\/ul>\n<h3>2) \uc0c1\uc218<\/h3>\n<ul>\n<li>\uc0c1\uc218\uc758 \uac12\uc740 \ud55c\ubc88 \uc120\uc5b8\ud55c \ub4a4 \ubc14\ub00c\uc9c0 \uc54a\uc74c.<\/li>\n<li>\uc0c1\uc218\ub97c \uc120\uc5b8 \ud560 \ub54c\uc5d0\ub294 <code>const<\/code> \uc0ac\uc6a9<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const a = 1;\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>3) var<\/h3>\n<ul>\n<li>\ubcc0\uc218\ub97c \uc120\uc5b8\ud558\ub294 \ub610 \ub2e4\ub978 \ubc29\ubc95<\/li>\n<li>\ub611\uac19\uc740 \uc774\ub984\uc73c\ub85c \uc5ec\ub7ec\ubc88 \uc120\uc5b8 \uac00\ub2a5<br \/>\n\u00a0<\/li>\n<\/ul>\n<h3>4) \ub370\uc774\ud130 \ud0c0\uc785<\/h3>\n<h4>\uc22b\uc790(Number) : \ubc14\ub85c \uac12 \ub300\uc785 \uac00\ub2a5<\/h4>\n<pre><code class=\"language-javascript line-numbers\">let value = 1;\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h4>\ubb38\uc790\uc5f4(String) : \uc791\uc740 \ub530\uc634\ud45c \ud639\uc740 \ud070 \ub530\uc634\ud45c\ub85c \uac10\uc2f8\uc11c \uc120\uc5b8<\/h4>\n<pre><code class=\"language-javascript line-numbers\">let text = 'hello';\nlet name = '\uc790\ubc14\uc2a4\ud06c\ub9bd\ud2b8';\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h4>\ucc38\/\uac70\uc9d3 (Boolean) : \ucc38\uc740 true, \uac70\uc9d3\uc740 false<\/h4>\n<pre><code class=\"language-javascript line-numbers\">let value = 1;\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h4>null : \uac12\uc774 \uc5c6\uc744\ub54c<\/h4>\n<pre><code class=\"language-javascript line-numbers\">const friend = null;\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h4>undefined : \uc544\uc9c1 \uac12\uc774 \uc124\uc815\ub418\uc9c0 \uc54a\uc740 \uac83\uc744 \uc758\ubbf8<\/h4>\n<pre><code class=\"language-javascript line-numbers\">let criminal;\nconsole.log(criminal);\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h2>3. \uc5f0\uc0b0\uc790<\/h2>\n<h3>1) \uc0b0\uc220 \uc5f0\uc0b0\uc790<\/h3>\n<ul>\n<li>\uc0b0\uc220 \uc5f0\uc0b0\uc790\ub294 \uc0ac\uce59\uc5f0\uc0b0\uacfc \uac19\uc740 \uc791\uc5c5\uc744 \ud558\ub294 \uc5f0\uc0b0\uc790\ub97c \uc758\ubbf8\ud569\ub2c8\ub2e4.<br \/>\n<code>+: \ub367\uc148<\/code><br \/>\n<code>-: \ubebc\uc148<\/code><br \/>\n<code>*: \uacf1\uc148<\/code><br \/>\n<code>\/: \ub098\ub217\uc148<\/code><br \/>\n\u00a0<\/li>\n<\/ul>\n<h3>2) \ub300\uc785 \uc5f0\uc0b0\uc790<\/h3>\n<ul>\n<li>\ub300\uc785 \uc5f0\uc0b0\uc790\ub294 \ud2b9\uc815 \uac12\uc5d0 \uc5f0\uc0b0\uc744 \ud55c \uac12\uc744 \ubc14\ub85c \uc124\uc815 \ud560 \ub54c \uc0ac\uc6a9 \ud560 \uc218 \uc788\ub294 \uc5f0\uc0b0\uc790<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">let a = 1;\na += 3;\na -= 3;\na *= 3;\na \/= 3;\nconsole.log(a);\n<\/code><\/pre>\n<ul>\n<li>\uacb0\uacfc\uac12 : <code>1<\/code><br \/>\n\u00a0<\/li>\n<\/ul>\n<h3>3) \ub17c\ub9ac \uc5f0\uc0b0\uc790<\/h3>\n<ul>\n<li>\ubd88\ub9ac\uc5b8 \ud0c0\uc785 (true \ud639\uc740 false)\ub97c \uc704\ud55c \uc5f0\uc0b0\uc790<br \/>\n<code>!: NOT<\/code><br \/>\n<code>&amp;&amp;: AND<\/code><br \/>\n<code>||: OR<\/code><br \/>\n\u00a0<\/li>\n<\/ul>\n<h3>4) \uc5f0\uc0b0 \uc21c\uc11c<\/h3>\n<ul>\n<li>NOT -> AND -> OR<br \/>\n\u00a0<\/li>\n<\/ul>\n<h3>5) \ube44\uad50 \uc5f0\uc0b0\uc790<\/h3>\n<ul>\n<li>\ub450 \uac12\uc744 \ube44\uad50 \ud560 \ub54c \uc0ac\uc6a9<\/li>\n<\/ul>\n<p>\u00a0<\/p>\n<h4>\ub450 \uac12\uc774 \uc77c\uce58\ud558\ub294\uc9c0 \ud655\uc778<\/h4>\n<h5>'=' \ubb38\uc790 3\uac1c \uc0ac\uc6a9<\/h5>\n<ul>\n<li>\uc77c\uce58\ud55c\ub2e4\uba74, true, \uc77c\uce58\ud558\uc9c0 \uc54a\ub294\ub2e4\uba74 false \uac00 \ub098\ud0c0\ub0a9\ub2c8\ub2e4. (\ud0c0\uc785 \uac80\uc0ac\uae4c\uc9c0)<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const a = 1;\nconst b = 1;\nconst equals = a === b;\nconsole.log(equals);\n<\/code><\/pre>\n<ul>\n<li>\uacb0\uacfc\uac12 : <code>true<\/code><br \/>\n\u00a0<\/li>\n<\/ul>\n<h5>'=' \ubb38\uc790 2\uac1c \uc0ac\uc6a9<\/h5>\n<ul>\n<li>\uc77c\uce58\ud55c\ub2e4\uba74, true, \uc77c\uce58\ud558\uc9c0 \uc54a\ub294\ub2e4\uba74 false \uac00 \ub098\ud0c0\ub0a9\ub2c8\ub2e4.(\ud0c0\uc785 \uac80\uc0ac X)<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const a = 1;\nconst b = 1;\nconst equals = a == b;\nconsole.log(equals);\n<\/code><\/pre>\n<p>\uacb0\uacfc: <code>true<\/code><br \/>\n\u00a0<\/p>\n<h6>ex1) \uc22b\uc790 1\uacfc \ubb38\uc790 '1'\uc774 \ub3d9\uc77c\ud55c \uac12\uc73c\ub85c \uac04\uc8fc<\/h6>\n<pre><code class=\"language-javascript line-numbers\">const a = 1;\nconst b = '1';\nconst equals = a == b;\nconsole.log(equals);\n<\/code><\/pre>\n<p>\uacb0\uacfc: <code>true<\/code><br \/>\n\u00a0<\/p>\n<h6>ex2) 0 \uacfc false \ub3c4 \uac19\uc740 \uac12\uc73c\ub85c \uac04\uc8fc<\/h6>\n<pre><code class=\"language-javascript line-numbers\">const a = 0;\nconst b = false;\nconst equals = a == b;\nconsole.log(equals);\n<\/code><\/pre>\n<p>\uacb0\uacfc: <code>true<\/code><br \/>\n\u00a0<\/p>\n<h6>ex3) undefined \uc640 null \ub3c4 \uac19\uc740 \uac12\uc73c\ub85c \uac04\uc8fc.<\/h6>\n<pre><code class=\"language-javascript line-numbers\">const a = null;\nconst b = undefined;\nconst equals = a == b;\nconsole.log(equals);\n<\/code><\/pre>\n<p>\uacb0\uacfc: <code>true<\/code><br \/>\n\u00a0<\/p>\n<h4>\ub450 \uac12\uc774 \uc77c\uce58\ud558\uc9c0 \uc54a\ub294\uc9c0 \ud655\uc778<\/h4>\n<h5>\ub450 \uac12\uc774 \uc77c\uce58\ud558\uc9c0 \uc54a\ub294\uc9c0 \ud655\uc778 \ud560 \ub54c\uc5d0\ub294 <code>!==<\/code> \ub97c \uc0ac\uc6a9<\/h5>\n<pre><code class=\"language-javascript line-numbers\">const value = 'a' !== 'b';\n<\/code><\/pre>\n<p>\uacb0\uacfc: <code>true<\/code><br \/>\n\u00a0<\/p>\n<h5><code>!=<\/code> \ub97c \uc0ac\uc6a9\ud558\uba74 \ud0c0\uc785 \uac80\uc0ac X<\/h5>\n<pre><code class=\"language-javascript line-numbers\">console.log(1 != '1');\nconsole.log(1 !== '1');\n<\/code><\/pre>\n<p>\uacb0\uacfc: <code>true<\/code><br \/>\n\u00a0<\/p>\n<h4>\ud06c\uace0 \uc791\uc74c<\/h4>\n<h5>\ub450 \uac12 \ube44\uad50<\/h5>\n<pre><code class=\"language-javascript line-numbers\">const a = 10;\nconst b = 15;\nconst c = 15;\n\nconsole.log(a &lt; b); \/\/ true\nconsole.log(b &gt; a); \/\/ true\nconsole.log(b &gt;= c); \/\/ true\nconsole.log(a &lt;= c); \/\/ true\nconsole.log(b &lt; c); \/\/ false;\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>6) \ubb38\uc790\uc5f4 \ubd99\uc774\uae30<\/h3>\n<h4><code>+<\/code> \ub97c \uc0ac\uc6a9\ud558\uc5ec \ubb38\uc790\uc5f4 \ubd99\uc774\uae30<\/h4>\n<pre><code class=\"language-javascript line-numbers\">const a = '\uc548\ub155';\nconst b = '\ud558\uc138\uc694';\nconsole.log(a + b);\n<\/code><\/pre>\n<p>\uacb0\uacfc: <code>\uc548\ub155\ud558\uc138\uc694<\/code><br \/>\n\u00a0<\/p>\n<h2>4. \uc870\uac74\ubb38<\/h2>\n<h3>1) if \ubb38<\/h3>\n<pre><code class=\"language-javascript line-numbers\">if (\uc870\uac74) {\n  \ucf54\ub4dc;\n}\n<\/code><\/pre>\n<h6>let \uacfc const \ub294 \ub2e4\ub978 \ube14\ub85d \ubc94\uc704\uc5d0\uc11c\ub294 \ub611\uac19\uc740 \uc774\ub984\uc73c\ub85c \uc120\uc5b8 \ud560 \uc218 \uc788\ub2e4.<\/h6>\n<pre><code class=\"language-javascript line-numbers\">const a = 1;\nif (true) {\n  const a = 2;\n  console.log('if\ubb38 \uc548\uc758 a \uac12\uc740 ' + a);\n}\nconsole.log('if\ubb38 \ubc16\uc758 a \uac12\uc740 ' + a);\n<\/code><\/pre>\n<ul>\n<li>\uacb0\uacfc<\/li>\n<\/ul>\n<pre><code class=\"line-numbers\">\"if\ubb38\uc758 \uc548\uc758 a \uac12\uc740 2\"\n\"if\ubb38 \ubc16\uc758 a \uac12\uc740 1\"\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>2) switch\/case \ubb38<\/h3>\n<pre><code class=\"language-javascript line-numbers\">const device = 'iphone';\n\nswitch (device) {\n  case 'iphone':\n    console.log('\uc544\uc774\ud3f0!');\n    break;\n  case 'ipad':\n    console.log('\uc544\uc774\ud328\ub4dc!');\n    break;\n  case 'galaxy note':\n    console.log('\uac24\ub7ed\uc2dc \ub178\ud2b8!');\n    break;\n  default:\n    console.log('\ubaa8\ub974\uaca0\ub124\uc694..');\n}\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h2>5. \ud568\uc218<\/h2>\n<h3>1) \ud568\uc218<\/h3>\n<pre><code class=\"language-javascript line-numbers\">function \ud568\uc218\uc774\ub984(\ub9e4\uac1c\ubcc0\uc218) {\n    \ucf54\ub4dc\n    return \uc6d0\ud558\ub294 \uac12;\n}\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>2) \ud654\uc0b4\ud45c \ud568\uc218<\/h3>\n<pre><code class=\"language-javascript line-numbers\">const \ud568\uc218\uc774\ub984 = (\ub9e4\uac1c\ubcc0\uc218) =&gt; {\n    \ucf54\ub4dc\n    return \uc6d0\ud558\ub294 \uac12;\n}\n<\/code><\/pre>\n<ul>\n<li>function \ud0a4\uc6cc\ub4dc \ub300\uc2e0\uc5d0 => \ubb38\uc790\ub97c \uc0ac\uc6a9\ud574\uc11c \ud568\uc218\ub97c \uad6c\ud604, \ud654\uc0b4\ud45c\uc758 \uc88c\uce21\uc5d0\ub294 \ud568\uc218\uc758 \ud30c\ub77c\ubbf8\ud130, \ud654\uc0b4\ud45c\uc758 \uc6b0\uce21\uc5d0\ub294 \ucf54\ub4dc \ube14\ub85d\uc774 \uc628\ub2e4.<\/li>\n<\/ul>\n<h5>\ud654\uc0b4\ud45c \ud568\uc218\uc640 \uc77c\ubc18 function \uc73c\ub85c \ub9cc\ub4e0 \ud568\uc218\uc640\uc758 \uc8fc\uc694 \ucc28\uc774\uc810\uc740 \ud654\uc0b4\ud45c \ud568\uc218\uc5d0\uc11c \uac00\ub974\ud0a4\ub294 this \uc640 function \uc5d0\uc11c \uac00\ub974\ud0a4\ub294 this \uac00 \uc11c\ub85c \ub2e4\ub974\ub2e4.<\/h5>\n<p>\u00a0<\/p>\n<h2>6. <a class=\"wp-editor-md-post-content-link\" href=\"https:\/\/blog.dozzing.kr\/?p=477\">\uac1d\uccb4<\/a><\/h2>\n<ul>\n<li>\ubcc0\uc218 \ud639\uc740 \uc0c1\uc218\ub97c \uc0ac\uc6a9\ud558\uac8c\ub420\ub54c \ud558\ub098\uc758 \uc774\ub984\uc5d0 \uc5ec\ub7ec \uc885\ub958\uc758 \uac12\uc744 \ub123\uc744 \uc218 \uc788\uac8c \ud574\uc900\ub2e4.<br \/>\n\u00a0<\/li>\n<\/ul>\n<h3>1) \uac1d\uccb4<\/h3>\n<ul>\n<li>\uac1d\uccb4\ub97c \uc120\uc5b8 \ud560 \ub54c\uc5d0\ub294 \uc774\ub807\uac8c <code>{ }<\/code> \ubb38\uc790 \uc548\uc5d0 \uc6d0\ud558\ub294 \uac12\ub4e4\uc744 \ub123\uace0, \ub0b4\uc6a9\uc740 <code>\ud0a4: \uc6d0\ud558\ub294\uac12<\/code>\uc758 \ud615\ud0dc\ub85c \ub123\uc5b4\uc57c \ud55c\ub2e4.<\/li>\n<li>\ud0a4\ub294 \uacf5\ubc31\uc774 \uc5c6\uc5b4\uc57c\ud558\uba70, \uc788\uc5b4\uc57c\ud55c\ub2e4\uba74 \ub530\uc634\ud45c\ub85c \uac10\uc2f8\uae30<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const sample = {\n  'key with space': true\n};\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>2) \ud568\uc218\uc5d0\uc11c \uac1d\uccb4\ub97c \ud30c\ub77c\ubbf8\ud130\ub85c \ubc1b\uae30<\/h3>\n<pre><code class=\"language-javascript line-numbers\">const ironMan = {\n  name: '\ud1a0\ub2c8 \uc2a4\ud0c0\ud06c',\n  actor: '\ub85c\ubc84\ud2b8 \ub2e4\uc6b0\ub2c8 \uc8fc\ub2c8\uc5b4',\n  alias: '\uc544\uc774\uc5b8\ub9e8'\n};\n\nconst captainAmerica = {\n  name: '\uc2a4\ud2f0\ube10 \ub85c\uc800\uc2a4',\n  actor: '\ud06c\ub9ac\uc2a4 \uc5d0\ubc18\uc2a4',\n  alias: '\ucea1\ud2f4 \uc544\uba54\ub9ac\uce74'\n};\n\nfunction print(hero) {\n  const text = `<span class=\"katex math inline\">{hero.alias}(<\/span>{hero.name}) \uc5ed\ud560\uc744 \ub9e1\uc740 \ubc30\uc6b0\ub294 ${\n    hero.actor\n  } \uc785\ub2c8\ub2e4.`;\n  console.log(text);\n}\n\nprint(ironMan);\nprint(captainAmerica);\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>3) \uac1d\uccb4 \ube44\uad6c\uc870\ud654 \ud560\ub2f9<\/h3>\n<pre><code class=\"language-javascript line-numbers\">const ironMan = {\n  name: '\ud1a0\ub2c8 \uc2a4\ud0c0\ud06c',\n  actor: '\ub85c\ubc84\ud2b8 \ub2e4\uc6b0\ub2c8 \uc8fc\ub2c8\uc5b4',\n  alias: '\uc544\uc774\uc5b8\ub9e8'\n};\n\nconst captainAmerica = {\n  name: '\uc2a4\ud2f0\ube10 \ub85c\uc800\uc2a4',\n  actor: '\ud06c\ub9ac\uc2a4 \uc5d0\ubc18\uc2a4',\n  alias: '\ucea1\ud2f4 \uc544\uba54\ub9ac\uce74'\n};\n\nfunction print({ alias, name, actor }) {\n  const text = `<span class=\"katex math inline\">{alias}(<\/span>{name}) \uc5ed\ud560\uc744 \ub9e1\uc740 \ubc30\uc6b0\ub294 ${actor} \uc785\ub2c8\ub2e4.`;\n  console.log(text);\n}\n\nprint(ironMan);\nprint(captainAmerica);\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>4) \uac1d\uccb4 \uc548\uc5d0 \ud568\uc218 \ub123\uae30<\/h3>\n<ul>\n<li>\ud568\uc218\uac00 \uac1d\uccb4\uc548\uc5d0 \ub4e4\uc5b4\uac00\uac8c \ub418\uba74, this \ub294 \uc790\uc2e0\uc774 \uc18d\ud574\uc788\ub294 \uac1d\uccb4\ub97c \uac00\ub974\ud0a8\ub2e4.<\/li>\n<li>\uac1d\uccb4 \uc548\uc5d0 \ud568\uc218\ub97c \ub123\uc744 \ub54c, \ud654\uc0b4\ud45c \ud568\uc218\ub85c \uc120\uc5b8\ud55c\ub2e4\uba74 \uc81c\ub300\ub85c \uc791\ub3d9\ud558\uc9c0 \uc54a\ub294\ub2e4.<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const dog = {\n  name: '\uba4d\uba4d\uc774',\n  sound: '\uba4d\uba4d!',\n  say: function() {\n    console.log(this.sound);\n  }\n};\n\ndog.say();\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>5) Getter \ud568\uc218\uc640 Setter \ud568\uc218<\/h3>\n<ul>\n<li>Getter \ud568\uc218\uc640 Setter \ud568\uc218\ub97c \uc0ac\uc6a9\ud558\uac8c \ub418\uba74 \ud2b9\uc815 \uac12\uc744 \ubc14\uafb8\ub824\uace0 \ud558\uac70\ub098, \ud2b9\uc815 \uac12\uc744 \uc870\ud68c\ud558\ub824\uace0 \ud560 \ub54c \uc6b0\ub9ac\uac00 \uc6d0\ud558\ub294 \ucf54\ub4dc\ub97c \uc2e4\ud589 \uc2dc\ud0ac \uc218 \uc788\ub2e4.<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">onst numbers = {\n  _a: 1,\n  _b: 2,\n  sum: 3,\n  calculate() {\n    console.log('calculate');\n    this.sum = this._a + this._b;\n  },\n  get a() {\n    return this._a;\n  },\n  get b() {\n    return this._b;\n  },\n  set a(value) {\n    console.log('a\uac00 \ubc14\ub01d\ub2c8\ub2e4.');\n    this._a = value;\n    this.calculate();\n  },\n  set b(value) {\n    console.log('b\uac00 \ubc14\ub01d\ub2c8\ub2e4.');\n    this._b = value;\n    this.calculate();\n  }\n};\n\nconsole.log(numbers.sum);\nnumbers.a = 5;\nnumbers.b = 7;\nnumbers.a = 9;\nconsole.log(numbers.sum);\nconsole.log(numbers.sum);\nconsole.log(numbers.sum);\n<\/code><\/pre>\n<ul>\n<li>\uacb0\uacfc<\/li>\n<\/ul>\n<pre><code class=\"line-numbers\">3\na\uac00 \ubc14\ub01d\ub2c8\ub2e4.\ncalculate\nb\uac00 \ubc14\ub01d\ub2c8\ub2e4.\ncalculate\na\uac00 \ubc14\ub01d\ub2c8\ub2e4.\ncalculate\n16\n16\n16\n<\/code><\/pre>\n<ul>\n<li>Setter \ud568\uc218\ub97c \uc124\uc815 \ud560 \ub54c\uc5d0\ub294 \ud568\uc218\uc758 \uc55e\ubd80\ubd84\uc5d0 set \ud0a4\uc6cc\ub4dc\ub97c \ubd99\uc778\ub2e4. Setter \ud568\uc218\ub97c \uc124\uc815\ud558\uace0 \ub098\uba74, <code>numbers.a = 5<\/code> \uc774\ub807\uac8c \uac12\uc744 \uc124\uc815\ud588\uc744 \ub54c <code>5<\/code> \ub97c \ud568\uc218\uc758 \ud30c\ub77c\ubbf8\ud130\ub85c \ubc1b\uc544\uc624\uac8c \ub41c\ub2e4. \uc704 \ucf54\ub4dc\uc5d0\uc11c\ub294 \uac1d\uccb4 \uc548\uc5d0 <code>_a<\/code>, <code>_b<\/code> \ub77c\ub294 \uc22b\uc790\ub97c \uc120\uc5b8\ud574\uc8fc\uace0, \uc774 \uac12\ub4e4\uc744 \uc704\ud55c Getter \uc640 Setter \ud568\uc218\ub97c \uc124\uc815\ud588\ub2e4.<br \/>\n\u00a0<\/li>\n<\/ul>\n<h2>7. \ubc30\uc5f4<\/h2>\n<ul>\n<li>\ubc30\uc5f4\uc740 \uc5ec\ub7ec\uac1c\uc758 \ud56d\ubaa9\ub4e4\uc774 \ub4e4\uc5b4\uc788\ub294 \ub9ac\uc2a4\ud2b8<\/li>\n<li>\ubc30\uc5f4\uc744 \uc120\uc5b8 \ud560 \ub54c\uc5d0\ub294 <code>[  ]<\/code> \uc0ac\uc6a9.<br \/>\n\u00a0<\/li>\n<\/ul>\n<h3>1) \uac1d\uccb4 \ubc30\uc5f4 \uc120\uc5b8<\/h3>\n<pre><code class=\"language-javascript line-numbers\">const objects = [{ name: '\uba4d\uba4d\uc774' }, { name: '\uc57c\uc639\uc774' }];\n\nconsole.log(objects);\nconsole.log(objects[0]);\nconsole.log(objects[1]);\n<\/code><\/pre>\n<ul>\n<li>\uacb0\uacfc<br \/>\n<a class=\"wp-editor-md-post-content-link\" href=\"https:\/\/blog.dozzing.kr\/wp-content\/uploads\/2023\/08\/wp_editor_md_f26c0aa63ef20925c76721a94724e9f7.jpg\"><img decoding=\"async\" src=\"https:\/\/blog.dozzing.kr\/wp-content\/uploads\/2023\/08\/wp_editor_md_f26c0aa63ef20925c76721a94724e9f7.jpg\" alt=\"\" \/><\/a><br \/>\n\u00a0<\/li>\n<\/ul>\n<h3>2) \ubc30\uc5f4\uc5d0 \uc0c8 \ud56d\ubaa9 \ucd94\uac00\ud558\uae30<\/h3>\n<pre><code class=\"language-javascript line-numbers\">const objects = [{ name: '\uba4d\uba4d\uc774' }, { name: '\uc57c\uc639\uc774' }];\n\nobjects.push({\n  name: '\uba4d\ubb49\uc774'\n});\n\nconsole.log(objects);\n<\/code><\/pre>\n<ul>\n<li>\uacb0\uacfc<br \/>\n<a class=\"wp-editor-md-post-content-link\" href=\"https:\/\/blog.dozzing.kr\/wp-content\/uploads\/2023\/08\/wp_editor_md_9c91bf5f3b58f14f10e8720750e61a46.jpg\"><img decoding=\"async\" src=\"https:\/\/blog.dozzing.kr\/wp-content\/uploads\/2023\/08\/wp_editor_md_9c91bf5f3b58f14f10e8720750e61a46.jpg\" alt=\"\" \/><\/a><br \/>\n\u00a0<\/li>\n<\/ul>\n<h3>3) \ubc30\uc5f4\uc758 \ud06c\uae30 \uc54c\uc544\ub0b4\uae30<\/h3>\n<ul>\n<li><code>length<\/code> \uac12\uc744 \ud655\uc778<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const objects = [{ name: '\uba4d\uba4d\uc774' }, { name: '\uc57c\uc639\uc774' }];\n\nconsole.log(objects.length);\n\nobjects.push({\n  name: '\uba4d\ubb49\uc774'\n});\n\nconsole.log(objects.length);\n<\/code><\/pre>\n<ul>\n<li>\uacb0\uacfc<\/li>\n<\/ul>\n<pre><code class=\"line-numbers\">2\n3\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h2>8. \ubc18\ubcf5\ubb38<\/h2>\n<h3>1) for<\/h3>\n<pre><code class=\"language-javascript line-numbers\">for (\ucd08\uae30 \uad6c\ubb38; \uc870\uac74 \uad6c\ubb38; \ubcc0\ud654 \uad6c\ubb38;) {\n  \ucf54\ub4dc\n}\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>2) while<\/h3>\n<pre><code class=\"language-javascript line-numbers\">while (\uc870\uac74 \uad6c\ubb38) {\n  \ucf54\ub4dc\n}\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>3) for...of<\/h3>\n<ul>\n<li><code>for...of<\/code>\ubb38\uc740 \ubc30\uc5f4\uc5d0 \uad00\ud55c \ubc18\ubcf5\ubb38\uc744 \ub3cc\ub9ac\uae30 \uc704\ud574\uc11c \ub9cc\ub4e4\uc5b4\uc9c4 \ubc18\ubcf5\ubb38<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">let numbers = [10, 20, 30, 40, 50];\nfor (let number of numbers) {\n  console.log(number);\n}\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>4) \uac1d\uccb4\ub97c \uc704\ud55c \ubc18\ubcf5\ubb38 for...in<\/h3>\n<ul>\n<li>\uac1d\uccb4\uc758 \uc815\ubcf4\ub97c \ubc30\uc5f4 \ud615\ud0dc\ub85c \ubc1b\uc544\uc62c \uc218\uc788\ub294 \ud568\uc218<\/li>\n<\/ul>\n<pre><code class=\"line-numbers\">Object.entries: [[\ud0a4, \uac12], [\ud0a4, \uac12]] \ud615\ud0dc\uc758 \ubc30\uc5f4\ub85c \ubcc0\ud658\nObject.keys: [\ud0a4, \ud0a4, \ud0a4] \ud615\ud0dc\uc758 \ubc30\uc5f4\ub85c \ubcc0\ud658\nObject.values: [\uac12, \uac12, \uac12] \ud615\ud0dc\uc758 \ubc30\uc5f4\ub85c \ubcc0\ud658\n<\/code><\/pre>\n<p>\uac1d\uccb4\uac00 \uc9c0\ub2c8\uace0 \uc788\ub294 \uac12\uc5d0 \ub300\ud558\uc5ec \ubc18\ubcf5\uc744 \ud558\uace0 \uc2f6\ub2e4\uba74 \uc704 \ud568\uc218\ub4e4\uc744 \uc0ac\uc6a9 \ub610\ub294 for...in \uad6c\ubb38\uc744 \uc0ac\uc6a9<\/p>\n<pre><code class=\"language-javascript line-numbers\">const doggy = {\n  name: '\uba4d\uba4d\uc774',\n  sound: '\uba4d\uba4d',\n  age: 2\n};\n\nfor (let key in doggy) {\n  console.log(`<span class=\"katex math inline\">{key}:<\/span>{doggy[key]}`);\n}\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>5) \uc5f0\uc2b5\ubb38\uc81c<\/h3>\n<ul>\n<li>\uc22b\uc790\ub85c \uc774\ub8e8\uc5b4\uc9c4 \ubc30\uc5f4\uc774 \uc8fc\uc5b4\uc84c\uc744 \ub54c, \ud574\ub2f9 \uc22b\uc790 \ubc30\uc5f4\uc548\uc5d0 \ub4e4\uc5b4\uc788\ub294 \uc22b\uc790 \uc911 3\ubcf4\ub2e4 \ud070 \uc22b\uc790\ub85c\ub9cc \uc774\ub8e8\uc5b4\uc9c4 \ubc30\uc5f4\uc744 \uc0c8\ub85c \ub9cc\ub4e4\uc5b4\uc11c \ubc18\ud658\ud574\ubcf4\uc138\uc694.<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">function biggerThanThree(numbers) {\n  const N = [];\n  for(let i = 0; i &lt;= numbers.length; i++){\n    if (numbers[i] &gt; 3) N.push(numbers[i]);\n  }\n  return N;\n}\n\nconst numbers = [1, 2, 3, 4, 5, 6, 7];\nconsole.log(biggerThanThree(numbers)); \/\/ \uacb0\uacfc \uac12 [4, 5, 6, 7]\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h2>9. \ubc30\uc5f4 \ub0b4\uc7a5\ud568\uc218<\/h2>\n<h3>1) forEach<\/h3>\n<pre><code class=\"language-javascript line-numbers\">function biggerThanThree(numbers) {\n  const N = [];\n  for(let i = 0; i &lt;= numbers.length; i++){\n    if (numbers[i] &gt; 3) N.push(numbers[i]);\n  }\n  return N;\n}\n\nconst numbers = [1, 2, 3, 4, 5, 6, 7];\nconsole.log(biggerThanThree(numbers)); \/\/ \uacb0\uacfc \uac12 [4, 5, 6, 7]\n<\/code><\/pre>\n<p>\u2b07 forEach\ub97c \uc0ac\uc6a9\ud558\uba74<\/p>\n<pre><code class=\"language-javascript line-numbers\">function biggerThanThree(numbers) {\n  const N = [];\n  numbers.forEach ( n =&gt; {\n    if(n &gt; 3) N.push(n);\n  });\n  return N;\n}\n\nconst numbers = [1, 2, 3, 4, 5, 6, 7];\nconsole.log(biggerThanThree(numbers)); \/\/ \uacb0\uacfc \uac12 [4, 5, 6, 7]\n<\/code><\/pre>\n<ul>\n<li>forEach \ud568\uc218\uc758 \ud30c\ub77c\ubbf8\ud130\ub85c\ub294, \uac01 \uc6d0\uc18c\uc5d0 \ub300\ud558\uc5ec \ucc98\ub9ac\ud558\uace0 \uc2f6\uc740 \ucf54\ub4dc\ub97c \ud568\uc218\ub85c \ub123\uc5b4\uc90c. \uc774 \ud568\uc218\uc758 \ud30c\ub77c\ubbf8\ud130 hero\ub294 \uac01 \uc6d0\uc18c\ub97c \uac00\ub974\ud0a8\ub2e4.<\/li>\n<li>\ud568\uc218\ud615\ud0dc\uc758 \ud30c\ub77c\ubbf8\ud130\ub97c \uc804\ub2ec\ud558\ub294 \uac83\uc744 \ucf5c\ubc31\ud568\uc218 \ub77c\uace0 \ubd80\ub978\ub2e4. \ud568\uc218\ub97c \ub4f1\ub85d\ud574\uc8fc\uba74, forEach \uac00 \uc2e4\ud589<br \/>\n\u00a0<\/li>\n<\/ul>\n<h3>2) map<\/h3>\n<ul>\n<li>map \uc740 \ubc30\uc5f4 \uc548\uc758 \uac01 \uc6d0\uc18c\ub97c \ubcc0\ud658 \ud560 \ub54c \uc0ac\uc6a9<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">function biggerThanThree(numbers) {\n  const N = [];\n  numbers.forEach ( n =&gt; {\n    if(n &gt; 3) N.push(n);\n  });\n  return N;\n}\n\nconst numbers = [1, 2, 3, 4, 5, 6, 7];\nconsole.log(biggerThanThree(numbers)); \/\/ \uacb0\uacfc \uac12 [4, 5, 6, 7]\n\nexport default biggerThanThree;\n<\/code><\/pre>\n<p>\u2b07 map\uc744 \uc0ac\uc6a9\ud558\uba74<\/p>\n<pre><code class=\"language-javascript line-numbers\">function biggerThanThree(numbers) {\n  const N = numbers.map(n =&gt; {\n    if(n&gt;3) return n;\n  }).filter(data =&gt; data);\n  return N;\n}\nconst numbers = [1, 2, 3, 4, 5, 6, 7];\nconsole.log(biggerThanThree(numbers)); \/\/ \uacb0\uacfc \uac12 [4, 5, 6, 7]\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>3) indexOf<\/h3>\n<ul>\n<li><code>indexOf<\/code>\ub294 \uc6d0\ud558\ub294 \ud56d\ubaa9\uc774 \uba87\ubc88\uc9f8 \uc6d0\uc18c\uc778\uc9c0 \ucc3e\uc544\uc8fc\ub294 \ud568\uc218<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const dogs = ['\ucfe0\ud0a4', '\ucfe0\ub9dd', '\ucfe0\ub871', '\uc0c8\uc6b0'];\nconst index = dogs.indexOf('\ucfe0\ub871');\nconsole.log(index); \/\/ \uacb0\uacfc \uac12 2\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>4) findIndex<\/h3>\n<ul>\n<li><code>indexOf<\/code>\ud568\uc218\ub85c\ub294 \ubc30\uc5f4 \uc548\uc5d0 \uc788\ub294 \uac12\uc774 \uac1d\uccb4\uc774\uac70\ub098, \ubc30\uc5f4\uc774\ub77c\uba74 \ucc3e\uc744 \uc218 \uc5c6\ub2e4 -> \uc774\ub7f4\ub550 <code>findIndex<\/code>\ub97c \uc0ac\uc6a9 !<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const todos = [\n  {\n    id: 1,\n    text: '\uc790\ubc14\uc2a4\ud06c\ub9bd\ud2b8 \uc785\ubb38',\n    done: true\n  },\n  {\n    id: 2,\n    text: '\ud568\uc218 \ubc30\uc6b0\uae30',\n    done: true\n  },\n  {\n    id: 3,\n    text: '\uac1d\uccb4\uc640 \ubc30\uc5f4 \ubc30\uc6b0\uae30',\n    done: true\n  },\n  {\n    id: 4,\n    text: '\ubc30\uc5f4 \ub0b4\uc7a5\ud568\uc218 \ubc30\uc6b0\uae30',\n    done: false\n  }\n];\n\nconst index = todos.findIndex(todo =&gt; todo.id === 3);\nconsole.log(index); \/\/ \uacb0\uacfc \uac12 2\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>5) find<\/h3>\n<ul>\n<li>\ucc3e\uc544\ub0b8 \uac12 \uc790\uccb4\ub97c \ubc18\ud658<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const todos = [\n  {\n    id: 1,\n    text: '\uc790\ubc14\uc2a4\ud06c\ub9bd\ud2b8 \uc785\ubb38',\n    done: true\n  },\n  {\n    id: 2,\n    text: '\ud568\uc218 \ubc30\uc6b0\uae30',\n    done: true\n  },\n  {\n    id: 3,\n    text: '\uac1d\uccb4\uc640 \ubc30\uc5f4 \ubc30\uc6b0\uae30',\n    done: true\n  },\n  {\n    id: 4,\n    text: '\ubc30\uc5f4 \ub0b4\uc7a5\ud568\uc218 \ubc30\uc6b0\uae30',\n    done: false\n  }\n];\n\nconst todo = todos.find(todo =&gt; todo.id === 3);\nconsole.log(todo);\n<\/code><\/pre>\n<ul>\n<li>\uacb0\uacfc : <code>{id: 3, text: \"\uac1d\uccb4\uc640 \ubc30\uc5f4 \ubc30\uc6b0\uae30\", done: true}<\/code><\/li>\n<\/ul>\n<p>\u00a0<\/p>\n<h3>6) filter<\/h3>\n<ul>\n<li>\ubc30\uc5f4\uc5d0\uc11c \ud2b9\uc815 \uc870\uac74\uc744 \ub9cc\uc871\ud558\ub294 \uac12\ub4e4\ub9cc \ub530\ub85c \ucd94\ucd9c\ud558\uc5ec \uc0c8\ub85c\uc6b4 \ubc30\uc5f4\uc744 \ub9cc\ub4e0\ub2e4.<\/li>\n<li>todos \ubc30\uc5f4\uc5d0\uc11c done \uac12\uc774 false \uc778 \ud56d\ubaa9\ub4e4\ub9cc \ub530\ub85c \ucd94\ucd9c\ud574\uc11c \uc0c8\ub85c\uc6b4 \ubc30\uc5f4 \uc0dd\uc131<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const todos = [\n  {\n    id: 1,\n    text: '\uc790\ubc14\uc2a4\ud06c\ub9bd\ud2b8 \uc785\ubb38',\n    done: true\n  },\n  {\n    id: 2,\n    text: '\ud568\uc218 \ubc30\uc6b0\uae30',\n    done: true\n  },\n  {\n    id: 3,\n    text: '\uac1d\uccb4\uc640 \ubc30\uc5f4 \ubc30\uc6b0\uae30',\n    done: true\n  },\n  {\n    id: 4,\n    text: '\ubc30\uc5f4 \ub0b4\uc7a5\ud568\uc218 \ubc30\uc6b0\uae30',\n    done: false\n  }\n];\n\nconst tasksNotDone = todos.filter(todo =&gt; todo.done === false);\nconsole.log(tasksNotDone);\n<\/code><\/pre>\n<ul>\n<li>\uacb0\uacfc<\/li>\n<\/ul>\n<pre><code class=\"line-numbers\">[\n  {\n    id: 4,\n    text: '\ubc30\uc5f4 \ub0b4\uc7a5 \ud568\uc218 \ubc30\uc6b0\uae30',\n    done: false\n  }\n];\n<\/code><\/pre>\n<p>\u2b07 \uc544\ub798\ucc98\ub7fc\ub3c4 \uc0ac\uc6a9\uac00\ub2a5<\/p>\n<pre><code class=\"language-javascript line-numbers\">const tasksNotDone = todos.filter(todo =&gt; !todo.done);\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>7) splice<\/h3>\n<ul>\n<li>\ubc30\uc5f4\uc5d0\uc11c \ud2b9\uc815 \ud56d\ubaa9\uc744 \uc81c\uac70\ud560 \ub54c \uc0ac\uc6a9<\/li>\n<li>splice \ub97c \uc0ac\uc6a9 \ud560 \ub54c \uccab\ubc88\uc9f8 \ud30c\ub77c\ubbf8\ud130\ub294 \uc5b4\ub5a4 \uc778\ub371\uc2a4\ubd80\ud130 \uc9c0\uc6b8\uc9c0\ub97c \uc758\ubbf8\ud558\uace0 \ub450\ubc88\uc9f8 \ud30c\ub77c\ubbf8\ud130\ub294 \uadf8 \uc778\ub371\uc2a4\ubd80\ud130 \uba87\uac1c\ub97c \uc9c0\uc6b8\uc9c0\ub97c \uc758\ubbf8\ud55c\ub2e4.<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const numbers = [10, 20, 30, 40];\nconst index = numbers.indexOf(30);\nnumbers.splice(index, 1);\nconsole.log(numbers);\n<\/code><\/pre>\n<ul>\n<li>\uacb0\uacfc : <code>[10, 20, 40]<\/code><br \/>\n\u00a0<\/li>\n<\/ul>\n<h3>8) slice<\/h3>\n<ul>\n<li>\ubc30\uc5f4\uc744 \uc798\ub77c\ub0bc \ub54c \uc0ac\uc6a9, \uae30\uc874\uc758 \ubc30\uc5f4\uc740 \uac74\ub4e4\uc774\uc9c0 \uc54a\ub294\ub2e4.<\/li>\n<li>slice \uc5d0\ub294 \ub450\uac1c\uc758 \ud30c\ub77c\ubbf8\ud130\ub97c \ub123\uac8c \ub418\ub294\ub370 \uccab\ubc88\uc9f8 \ud30c\ub77c\ubbf8\ud130\ub294 \uc5b4\ub514\uc11c\ubd80\ud130 \uc790\ub97c\uc9c0, \ub450\ubc88\uc9f8 \ud30c\ub77c\ubbf8\ud130\ub294 \uc5b4\ub514\uae4c\uc9c0 \uc790\ub97c\uc9c0\ub97c \uc758\ubbf8\ud55c\ub2e4.<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const numbers = [10, 20, 30, 40];\nconst sliced = numbers.slice(0, 2); \/\/ 0\ubd80\ud130 \uc2dc\uc791\ud574\uc11c 2\uc804\uae4c\uc9c0\n\nconsole.log(sliced); \/\/ [10, 20]\nconsole.log(numbers); \/\/ [10, 20, 30, 40]\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>9) shift \uc640 pop<\/h3>\n<ul>\n<li><code>shift<\/code> : \uccab\ubc88\uc9f8 \uc6d0\uc18c\ub97c \ubc30\uc5f4\uc5d0\uc11c \ucd94\ucd9c\ud574\uc900\ub2e4. (\ucd94\ucd9c\ud558\ub294 \uacfc\uc815\uc5d0\uc11c \ubc30\uc5f4\uc5d0\uc11c \ud574\ub2f9 \uc6d0\uc18c\ub294 \uc0ac\ub77c\uc9c4\ub2e4.)<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const numbers = [10, 20, 30, 40];\nconst value = numbers.shift();\nconsole.log(value);\nconsole.log(numbers);\n<\/code><\/pre>\n<ul>\n<li>\uacb0\uacfc<\/li>\n<\/ul>\n<pre><code class=\"line-numbers\">10\n[20, 30, 40]\n<\/code><\/pre>\n<ul>\n<li><code>pop<\/code> : <code>push<\/code>\uc758 \ubc18\ub300, <code>push<\/code>\ub294 \ubc30\uc5f4\uc758 \ub9e8 \ub9c8\uc9c0\ub9c9\uc5d0 \uc0c8 \ud56d\ubaa9\uc744 \ucd94\uac00, <code>pop<\/code>\uc740 \ub9e8 \ub9c8\uc9c0\ub9c9 \ud56d\ubaa9\uc744 \ucd94\ucd9c<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const numbers = [10, 20, 30, 40];\nconst value = numbers.pop();\nconsole.log(value);\nconsole.log(numbers);\n<\/code><\/pre>\n<ul>\n<li>\uacb0\uacfc<\/li>\n<\/ul>\n<pre><code class=\"line-numbers\">40\n[10, 20, 30]\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>10) unshift<\/h3>\n<ul>\n<li><code>shift<\/code>\uc758 \ubc18\ub300, \ubc30\uc5f4\uc758 \ub9e8 \uc55e\uc5d0 \uc0c8 \uc6d0\uc18c \ucd94\uac00<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const numbers = [10, 20, 30, 40];\nnumbers.unshift(5);\nconsole.log(numbers);\n<\/code><\/pre>\n<ul>\n<li>\uacb0\uacfc : <code>[5, 10, 20, 30, 40]<\/code><br \/>\n\u00a0<\/li>\n<\/ul>\n<h3>11) concat<\/h3>\n<ul>\n<li>\uc5ec\ub7ec\uac1c\uc758 \ubc30\uc5f4\uc744 \ud558\ub098\uc758 \ubc30\uc5f4\ub85c \ud569\uccd0\uc90c<\/li>\n<li>\uae30\uc874\ud568\uc218\uc5d0 \uc601\ud56d\uc744 \uc8fc\uc9c0 \uc54a\uc74c.<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const arr1 = [1, 2, 3];\nconst arr2 = [4, 5, 6];\nconst concated = arr1.concat(arr2);\n\nconsole.log(concated);\n<\/code><\/pre>\n<ul>\n<li>\uacb0\uacfc : <code>[1, 2, 3, 4, 5, 6];<\/code><br \/>\n\u00a0<\/li>\n<\/ul>\n<h3>12) join<\/h3>\n<ul>\n<li>\ubc30\uc5f4 \uc548\uc758 \uac12\ub4e4\uc744 \ubb38\uc790\uc5f4 \ud615\ud0dc\ub85c \ud569\uccd0\uc90c.<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const array = [1, 2, 3, 4, 5];\nconsole.log(array.join()); \/\/ 1,2,3,4,5\nconsole.log(array.join(' ')); \/\/ 1 2 3 4 5\nconsole.log(array.join(', ')); \/\/ 1, 2, 3, 4, 5\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>13) reduce<\/h3>\n<ul>\n<li>\uccab\ubc88\uc9f8 \ud30c\ub77c\ubbf8\ud130\ub294 accumulator \uc640 current \ub97c \ud30c\ub77c\ubbf8\ud130\ub85c \uac00\uc838\uc640\uc11c \uacb0\uacfc\ub97c \ubc18\ud658\ud558\ub294 \ucf5c\ubc31\ud568\uc218, \ub450\ubc88\uc9f8 \ud30c\ub77c\ubbf8\ud130\ub294 reduce \ud568\uc218\uc5d0\uc11c \uc0ac\uc6a9 \ud560 \ucd08\uae43\uac12<\/li>\n<li>\ubc30\uc5f4\uc758 \ucd1d \ud569 \uad6c\ud558\uae30<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const numbers = [1, 2, 3, 4, 5];\nlet sum = numbers.reduce((accumulator, current) =&gt; accumulator + current, 0);\n\nconsole.log(sum); \/\/ \uacb0\uacfc \uac12 : 15\n<\/code><\/pre>\n<ul>\n<li>\ubc30\uc5f4\uc758 \ud3c9\uade0 \uad6c\ud558\uae30<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">const numbers = [1, 2, 3, 4, 5];\nlet sum = numbers.reduce((accumulator, current, index, array) =&gt; {\n  if (index === array.length - 1) {\n    return (accumulator + current) \/ array.length;\n  }\n  return accumulator + current;\n}, 0);\n\nconsole.log(sum); \/\/ \uacb0\uacfc \uac12 : 3\n<\/code><\/pre>\n<p>\u00a0<\/p>\n<h3>14) \ud034\uc988<\/h3>\n<ul>\n<li>\uc22b\uc790 \ubc30\uc5f4\uc774 \uc8fc\uc5b4\uc84c\uc744 \ub54c 10\ubcf4\ub2e4 \ud070 \uc22b\uc790\uc758 \uac2f\uc218\ub97c \ubc18\ud658\ud558\ub294 \ud568\uc218\ub97c \ub9cc\ub4e4\uae30<\/li>\n<\/ul>\n<pre><code class=\"language-javascript line-numbers\">function countBiggerThanTen(numbers) {\n  let count = 0;\n  for(let number of numbers){\n    if(number&gt;10) count++;\n  }\n  return count;\n}\n\nconst count = countBiggerThanTen([1, 2, 3, 5, 10, 20, 30, 40, 50, 60]);\nconsole.log(count); \/\/ 5\n<\/code><\/pre>\n<p>\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\ud83d\udc33\ubca8\ub85c\ud37c\ud2b8\uc640 \ud568\uaed8\ud558\ub294 \ubaa8\ub358 \uc790\ubc14\uc2a4\ud06c\ub9bd\ud2b8\ub97c \ubcf4\uba74\uc11c \uc815\ub9ac\ud55c \uae00 \uc785\ub2c8\ub2e4 \ud83d\udc33 1. 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