{"id":120163,"date":"2022-02-13T06:00:56","date_gmt":"2022-02-12T21:00:56","guid":{"rendered":"https:\/\/anthem00.xsrv.jp\/2023_new_tcd\/?p=120163"},"modified":"2022-05-26T22:13:58","modified_gmt":"2022-05-26T13:13:58","slug":"javascript-boolean","status":"publish","type":"post","link":"https:\/\/anthem00.xsrv.jp\/2023_new_tcd\/2022\/02\/javascript-boolean.html","title":{"rendered":"\u3010JavaScript\u306e\u5165\u9580\u3011\u8ad6\u7406\u578b\uff08Boolean\uff09"},"content":{"rendered":"

\u3042\u308b\u6761\u4ef6\u4e0b\u3067\u5024\u3092true\uff08\u771f\uff09\u304bfalse\uff08\u507d\uff09\u304b\u5224\u5b9a\u3055\u305b\u308b\u305f\u3081\u306b\u3001\u4f7f\u308f\u308c\u3066\u3044\u308b\u306e\u304c\u8ad6\u7406\u578b\u3067\u3059\u3002JavaScript\u3067\u306f\u3001\u6761\u4ef6\u5206\u5c90\u3084\u7e70\u308a\u8fd4\u3057\u6587\u306a\u3069\u306e\u3055\u307e\u3056\u307e\u306a\u51e6\u7406\u3067\u8ad6\u7406\u5024\u304c\u5229\u7528\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n

\u305d\u3053\u3067\u4eca\u56de\u306f\u3001\u8ad6\u7406\u578b\u3068\u306f\u4f55\u304b\u3001\u307e\u305f\u305d\u306e\u5224\u5b9a\u7d50\u679c\u306b\u3064\u3044\u3066\u89e3\u8aac\u3057\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n

\u8ad6\u7406\u578b\uff08Boolean\uff09<\/h2>\n

\u8ad6\u7406\u578b\u304c\u6301\u3064\u5024\u306f\u3001true\u307e\u305f\u306ffalse\u306e2\u3064\u306e\u307f\u3067\u3059\u3002<\/p>\n

true\u306f\u771f\uff08\u6b63\u3057\u3044\uff09\u3092\u610f\u5473\u3057\u3001false\u306f\u507d\uff08\u6b63\u3057\u304f\u306a\u3044\uff09\u3092\u610f\u5473\u3057\u307e\u3059\u3002\u3053\u306etrue\u3084false\u306e\u5024\u306e\u3053\u3068\u3092\u300c\u8ad6\u7406\u5024\u300d\u307e\u305f\u306f\u300c\u771f\u507d\u5024\u300d\u3068\u547c\u3073\u307e\u3059\u3002<\/p>\n

typeof\u6f14\u7b97\u5b50\u3092\u4f7f\u3063\u3066true\u3068false\u306e\u578b\u3092\u8abf\u3079\u308b\u3068\"boolean\"<\/code>\u3068\u8868\u8a18\u3055\u308c\u307e\u3059\u3002<\/p>\n

\n
console.log(typeof true); \/\/ \"boolean\"\r\nconsole.log(typeof false); \/\/ \"boolean\"\r\n<\/code><\/pre>\n<\/div>\n
\u8ad6\u7406\u578b\u306f\u3001\u3053\u306e\u3088\u3046\u306btrue\u307e\u305f\u306ffalse\u306e\u5024\u3092\u683c\u7d0d\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
\n
let over16YearsOld = true; \/\/ 16\u6b73\u4ee5\u4e0a\u306fOK\r\nlet under15YearsOld = false; \/\/ 15\u6b73\u4ee5\u4e0b\u306fNG\r\n<\/code><\/pre>\n<\/div>\n
\u307e\u305f\u3001\u8ad6\u7406\u578b\u306f\u3001\u6bd4\u8f03\u306e\u5224\u5b9a\u3092\u3059\u308b\u969b\u306b\u3088\u304f\u5229\u7528\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n
\n
console.log(3 < 5); \/\/ true\r\nconsole.log('javascript' === 'JavaScript'); \/\/ false\r\n<\/code><\/pre>\n<\/div>\n
\u4f8b\u3048\u3070\u3001\u3042\u308b\u6761\u4ef6\u4e0b\u306b\u304a\u3044\u3066\u5024\u304c\u6b63\u3057\u3044\u5834\u5408\u306f1\u306e\u51e6\u7406\u3092\u3001\u6b63\u3057\u304f\u306a\u3044\u5834\u5408\u306f2\u306e\u51e6\u7406\u3092\u884c\u3044\u305f\u3044\u6642\u306a\u3069\u3067\u3059\u3002JavaScript\u3067\u306f\u3001if\u6587\u3084for\u6587\u306a\u3069\u304c\u8a72\u5f53\u3057\u307e\u3059\u3002<\/p>\n
\n
if (3 < 5) { \/\/ \u5024\u304ctrue\u306e\u305f\u3081\u30011\u306e\u51e6\u7406\u3092\u884c\u3046\r\n  console.log('1: \u5024\u306f\u6b63\u3057\u3044\u3067\u3059'); \r\n} else { \r\n  console.log('2: \u5024\u306f\u9593\u9055\u3044\u3067\u3059');\r\n}\r\n\r\n\/\/ \"1: \u5024\u306f\u6b63\u3057\u3044\u3067\u3059\"\r\n<\/code><\/pre>\n<\/div>\n
\u8ad6\u7406\u578b\u306e\u5224\u5b9a<\/h2>\n
\u3042\u308b\u6761\u4ef6\u4e0b\u306b\u304a\u3051\u308b\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u4f5c\u6210\u3059\u308b\u969b\u306b\u306f\u3001\u8ad6\u7406\u578b\u304ctrue\u3068\u5224\u5b9a\u3059\u308b\u304b\u3001false\u3068\u5224\u5b9a\u3059\u308b\u304b\u3092\u7406\u89e3\u3057\u3066\u304a\u304f\u3053\u3068\u304c\u5927\u5207\u3067\u3059\u3002<\/p>\n
\u3067\u306f\u3001\u3069\u306e\u3088\u3046\u306a\u5024\u304ctrue\u3068\u307f\u306a\u3055\u308c\u308b\u306e\u304b\u3001\u307e\u305ffalse\u3068\u307f\u306a\u3055\u308c\u308b\u306e\u304b\u306b\u3064\u3044\u3066\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n
\u3053\u3053\u3067\u306f\u3001if\u6587\u3092\u4f8b\u306b\u53d6\u308a\u4e0a\u3052\u306a\u304c\u3089\u8ad6\u7406\u578b\u306e\u5224\u5b9a\u3092\u89e3\u8aac\u3057\u3066\u3044\u304d\u307e\u3059\u3002
\n\u96e3\u3057\u3044\u3053\u3068\u306f\u53d6\u308a\u4e0a\u3052\u307e\u305b\u3093\u304c\u3001\u3042\u3089\u304b\u3058\u3081if\u6587\u306b\u3064\u3044\u3066\u5b66\u7fd2\u3057\u305f\u3044\u65b9\u306f\u4ee5\u4e0b\u306e\u8a18\u4e8b\u3092\u53c2\u8003\u306b\u3057\u3066\u304f\u3060\u3055\u3044\u3002
\n
\n    \n     \"\"\n    <\/a>\n    
\n     
\n      
\n       
2021.03.28<\/p>\n       
2022.05.26<\/p>\n      <\/div>\n      
\n       \u3010JavaScript\u306e\u5165\u9580\u3011\u6761\u4ef6\u5206\u5c90 -if\u6587<\/a>\n      <\/div>\n     <\/div>\n     
if\u6587\u306b\u3088\u308b\u6761\u4ef6\u5206\u5c90\u306f\u3001\u3055\u307e\u3056\u307e\u306a\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u3067\u826f\u304f\u4f7f\u7528\u3055\u308c\u3066\u304a\u308a\u3001JavaScript\u306b\u304a\u3044\u3066\u3082\u5fc5\u9808\u306e\u77e5\u8b58\u3067\u3059\u3002\r\n\r\n\u4eca\u56de\u306f\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u3092\u884c\u3046\u4e0a\u3067\u3001\u521d\u671f\u6bb5\u968e\u3067\u5b66\u3076if\u6587\u306e\u57fa\u672c\u3092\u521d\u5fc3\u8005\u5411\u3051\u306b\u5206\u304b\u308a\u3084\u3059\u304f\u89e3\u8aac\u3057\u3066\u3044\u304d\u307e\u3059\u3002\u3053\u306e\u8a18\u4e8b\u3092\u901a\u3057\u3066\u3001if\u6587\u3092\u6df1\u304f\u7406\u89e3\u3057\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002\r\nif\u6587\r\n\r\n...<\/span><\/p>\n    <\/div>\n   <\/div>\n<\/p>\n
false\u3068\u307f\u306a\u3055\u308c\u308b\u5024<\/h3>\n
\u307e\u305a\u306f\u3001false\u3068\u307f\u306a\u3055\u308c\u308b\u5024\u3067\u3059\u3002
\n\u305d\u306e\u4ed6\u306e\u5024\u306ftrue\u3068\u307f\u306a\u3055\u308c\u308b\u5024\u3068\u306a\u308b\u305f\u3081\u3001\u3053\u308c\u3089\u3092\u5148\u306b\u899a\u3048\u3066\u304a\u304f\u3068\u4fbf\u5229\u3067\u3059\u3002<\/p>\n
false\u3068\u306a\u308b\u5024\u306f8\u3064\u3042\u308a\u307e\u3059\u3002<\/p>\n
\n\n\n\n\n\n\n\n\n\n\n\n
\u5024<\/th>\n\u610f\u5473<\/th>\n<\/tr>\n<\/thead>\n
false<\/td>\nfalse\u30ad\u30fc\u30ef\u30fc\u30c9<\/td>\n<\/tr>\n
0<\/td>\n\u6570\u5024\u306e\u30bc\u30ed<\/td>\n<\/tr>\n
-0<\/td>\n\u6570\u5024\u306e\u30de\u30a4\u30ca\u30b9\u30bc\u30ed<\/td>\n<\/tr>\n
0n<\/td>\nBigInt\u578b\u306e0n<\/td>\n<\/tr>\n
“”<\/td>\n\u7a7a\u306e\u6587\u5b57\u5217<\/td>\n<\/tr>\n
null<\/td>\n\u5024\u304c\u5b58\u5728\u3057\u306a\u3044<\/td>\n<\/tr>\n
undefined<\/td>\n\u672a\u5b9a\u7fa9\u306e\u5024<\/td>\n<\/tr>\n
NaN<\/td>\n\u975e\u6570<\/td>\n<\/tr>\n<\/tbody>\n<\/table><\/div>\n
\u3053\u308c\u3089\u306e\u5024\u3092if\u6587\u306e\u6761\u4ef6\u5f0f\u306b\u8a18\u8ff0\u3059\u308b\u3068\u3001false\u3068\u8a55\u4fa1\u3055\u308c\u3001if\u30d6\u30ed\u30c3\u30af\u306e\u51e6\u7406\u306f\u5b9f\u884c\u3055\u308c\u307e\u305b\u3093\u3002<\/p>\n
\n
if (false) {}\r\nif (0) {}\r\nif (-0) {}\r\nif (0n) {}\r\nif (\"\") {}\r\nif (null) {}\r\nif (undefined) {}\r\nif (NaN) {}\r\n<\/code><\/pre>\n<\/div>\n
\u4ee5\u4e0b\u306f\u3001if\u6587\u306e\u6761\u4ef6\u5f0f\u306b\u7a7a\u306e\u6587\u5b57\u5217\u304c\u8a18\u8ff0\u3055\u308c\u3066\u3044\u308b\u305f\u3081\u3001false\u3068\u5224\u5b9a\u3055\u308c\u3001if\u30d6\u30ed\u30c3\u30af\u3092\u5b9f\u884c\u305b\u305a\u3001else\u30d6\u30ed\u30c3\u30af\u306e\u51e6\u7406\u304c\u5b9f\u884c\u3055\u308c\u307e\u3059\u3002<\/p>\n
\n
if (\"\") { \r\n  console.log('true');\r\n} else {\r\n  console.log('false'); \r\n}\r\n\r\n\/\/ \"false\"\r\n<\/code><\/pre>\n<\/div>\n
true\u3068\u307f\u306a\u3055\u308c\u308b\u5024<\/h3>\n
false\u3068\u307f\u306a\u3055\u308c\u308b\u5024\u4ee5\u5916\u306f\u3001\u3059\u3079\u3066true\u3068\u307f\u306a\u3055\u308c\u308b\u5024\u3067\u3059\u3002
\n\u4f8b\u3048\u3070\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u5024\u304c\u8a72\u5f53\u3057\u307e\u3059\u3002<\/p>\n
\n\n\n\n\n\n\n\n\n\n
\u5024<\/th>\n\u610f\u5473<\/th>\n<\/tr>\n<\/thead>\n
true<\/td>\ntrue\u30ad\u30fc\u30ef\u30fc\u30c9<\/td>\n<\/tr>\n
10<\/td>\n\u6570\u5024<\/td>\n<\/tr>\n
“\u6587\u5b57\u5217”<\/td>\n\u6587\u5b57\u5217<\/td>\n<\/tr>\n
1n<\/td>\n\u9577\u6574\u6570<\/td>\n<\/tr>\n
{}<\/td>\n\u30aa\u30d6\u30b8\u30a7\u30af\u30c8<\/td>\n<\/tr>\n
[]<\/td>\n\u914d\u5217<\/td>\n<\/tr>\n<\/tbody>\n<\/table><\/div>\n
\u3053\u308c\u3089\u306e\u5024\u3092if\u6587\u306e\u6761\u4ef6\u5f0f\u306b\u8a18\u8ff0\u3059\u308b\u3068\u3001true\u3068\u8a55\u4fa1\u3055\u308c\u3001if\u30d6\u30ed\u30c3\u30af\u306e\u51e6\u7406\u3092\u5b9f\u884c\u3057\u307e\u3059\u3002<\/p>\n
\n
if (true) {}\r\nif (10) {}\r\nif (\"\u6587\u5b57\u5217\") {}\r\nif (1n) {}\r\nif ({}) {}\r\nif ([]) {}<\/code><\/pre>\n<\/div>\n
\u4ee5\u4e0b\u306f\u3001if\u6587\u306e\u6761\u4ef6\u5f0f\u306b100\u3068\u3044\u3046\u6570\u5024\u304c\u8a18\u8ff0\u3055\u308c\u3066\u3044\u308b\u305f\u3081\u3001true\u3068\u5224\u5b9a\u3055\u308c\u3001if\u30d6\u30ed\u30c3\u30af\u306b\u66f8\u304b\u308c\u3066\u3044\u308b\u51e6\u7406\u304c\u5b9f\u884c\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n
\n
if (100) { \r\n  console.log('true');\r\n} else {\r\n  console.log('false'); \r\n}\r\n\r\n\/\/ \"true\"\r\n<\/code><\/pre>\n<\/div>\n
\u307e\u3068\u3081<\/h2>\n
\u4eca\u56de\u306f\u3001\u8ad6\u7406\u578b\u306b\u3064\u3044\u3066\u89e3\u8aac\u3057\u307e\u3057\u305f\u3002
\nif\u6587\u306e\u3088\u3046\u306a\u8ad6\u7406\u5024\u304c\u8981\u6c42\u3055\u308c\u308b\u5834\u9762\u3067\u306f\u3001\u5024\u304ctrue\u3068\u306a\u308b\u306e\u304bfalse\u3068\u306a\u308b\u306e\u304b\u7406\u89e3\u3057\u3066\u3044\u306a\u3044\u3068\u3001\u610f\u56f3\u3057\u305f\u51e6\u7406\u7d50\u679c\u3092\u5f97\u3089\u308c\u306a\u3044\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n
\u3053\u306e\u6a5f\u4f1a\u306btrue\u3068\u306a\u308b\u5024\u3001false\u3068\u306a\u308b\u5024\u3092\u899a\u3048\u3066\u304a\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n
\u5408\u308f\u305b\u3066\u8aad\u307f\u305f\u3044\u30c7\u30fc\u30bf\u578b\u5165\u9580\u30b7\u30ea\u30fc\u30ba<\/h2>\n
\u7b2c1\u56de\uff1a\u30c7\u30fc\u30bf\u578b\u3068typeof\u6f14\u7b97\u5b50<\/strong><\/a>
\n\u7b2c2\u56de\uff1a\u30c7\u30fc\u30bf\u578b -\u30d7\u30ea\u30df\u30c6\u30a3\u30d6<\/strong><\/a>
\n\u7b2c3\u56de\uff1a\u30c7\u30fc\u30bf\u578b -\u30aa\u30d6\u30b8\u30a7\u30af\u30c8<\/strong><\/a>
\n\u7b2c4\u56de\uff1a\u6587\u5b57\u5217\u578b\uff08String\uff09<\/strong><\/a>
\n\u7b2c5\u56de\uff1a\u6570\u5024\u578b\uff08Number\uff09<\/strong><\/a>
\n\u7b2c6\u56de\uff1a\u8ad6\u7406\u578b\uff08Boolean\uff09<\/strong><\/a>\uff08\u5f53\u8a18\u4e8b\uff09
\n\u7b2c7\u56de\uff1anull\u578b\u30fbundefined\u578b<\/strong><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"\u3042\u308b\u6761\u4ef6\u4e0b\u3067\u5024\u3092true\uff08\u771f\uff09\u304bfalse\uff08\u507d\uff09\u304b\u5224\u5b9a\u3055\u305b\u308b\u305f\u3081\u306b\u3001\u4f7f\u308f\u308c\u3066\u3044\u308b\u306e\u304c\u8ad6\u7406\u578b\u3067\u3059\u3002JavaScript\u3067\u306f\u3001\u6761\u4ef6\u5206\u5c90\u3084\u7e70\u308a\u8fd4\u3057\u6587\u306a\u3069\u306e\u3055\u307e\u3056\u307e\u306a\u51e6\u7406\u3067\u8ad6\u7406\u5024\u304c\u5229\u7528\u3055\u308c\u3066\u3044\u307e\u3059\u3002 \u305d\u3053\u3067\u4eca\u56de\u306f\u3001\u8ad6\u7406\u578b\u3068\u306f\u4f55\u304b […]","protected":false},"author":1,"featured_media":120432,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":false,"footnotes":""},"categories":[1141],"tags":[964],"class_list":["post-120163","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-javascript-intro","tag-javascript"],"_links":{"self":[{"href":"https:\/\/anthem00.xsrv.jp\/2023_new_tcd\/wp-json\/wp\/v2\/posts\/120163","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/anthem00.xsrv.jp\/2023_new_tcd\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/anthem00.xsrv.jp\/2023_new_tcd\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/anthem00.xsrv.jp\/2023_new_tcd\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/anthem00.xsrv.jp\/2023_new_tcd\/wp-json\/wp\/v2\/comments?post=120163"}],"version-history":[{"count":0,"href":"https:\/\/anthem00.xsrv.jp\/2023_new_tcd\/wp-json\/wp\/v2\/posts\/120163\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/anthem00.xsrv.jp\/2023_new_tcd\/wp-json\/wp\/v2\/media\/120432"}],"wp:attachment":[{"href":"https:\/\/anthem00.xsrv.jp\/2023_new_tcd\/wp-json\/wp\/v2\/media?parent=120163"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/anthem00.xsrv.jp\/2023_new_tcd\/wp-json\/wp\/v2\/categories?post=120163"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/anthem00.xsrv.jp\/2023_new_tcd\/wp-json\/wp\/v2\/tags?post=120163"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}