{"id":2135,"date":"2025-03-01T00:07:15","date_gmt":"2025-02-28T16:07:15","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=2135"},"modified":"2025-03-01T00:07:15","modified_gmt":"2025-02-28T16:07:15","slug":"javascript-boolean%ef%bc%88%e5%b8%83%e5%b0%94%ef%bc%89-%e5%af%b9%e8%b1%a1","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/03\/01\/javascript-boolean%ef%bc%88%e5%b8%83%e5%b0%94%ef%bc%89-%e5%af%b9%e8%b1%a1\/","title":{"rendered":"JavaScript Boolean\uff08\u5e03\u5c14\uff09 \u5bf9\u8c61"},"content":{"rendered":"\n

\u5728 JavaScript \u4e2d\uff0cBoolean\uff08\u5e03\u5c14\uff09<\/strong> \u662f\u4e00\u79cd\u8868\u793a\u903b\u8f91\u503c\u7684\u6570\u636e\u7c7b\u578b\uff0c\u53ea\u6709\u4e24\u4e2a\u53ef\u80fd\u7684\u503c\uff1atrue<\/code> \u548c false<\/code>\u3002Boolean<\/code> \u7c7b\u578b\u7528\u4e8e\u6761\u4ef6\u5224\u65ad\u3001\u903b\u8f91\u8fd0\u7b97\u4ee5\u53ca\u63a7\u5236\u7a0b\u5e8f\u6d41\u7a0b\u7b49\u65b9\u9762\u3002<\/p>\n\n\n\n

1. Boolean \u7684\u57fa\u672c\u6982\u5ff5<\/strong><\/h3>\n\n\n\n
    \n
  • true<\/code><\/strong>\uff1a\u8868\u793a\u771f\u3002<\/li>\n\n\n\n
  • false<\/code><\/strong>\uff1a\u8868\u793a\u5047\u3002<\/li>\n<\/ul>\n\n\n\n

    \u5e03\u5c14\u503c\u901a\u5e38\u7528\u5728\u6761\u4ef6\u5224\u65ad\u8bed\u53e5\u4e2d\uff0c\u5982 if<\/code> \u8bed\u53e5\u3001while<\/code> \u5faa\u73af\u7b49\u3002<\/p>\n\n\n\n

    2. \u521b\u5efa Boolean \u5bf9\u8c61<\/strong><\/h3>\n\n\n\n

    2.1 \u76f4\u63a5\u4f7f\u7528\u5b57\u9762\u91cf\uff08\u63a8\u8350\uff09<\/strong><\/h4>\n\n\n\n
    let isActive = true;\nlet isComplete = false;\n\nconsole.log(isActive);  \/\/ \u8f93\u51fa\uff1atrue\nconsole.log(isComplete);  \/\/ \u8f93\u51fa\uff1afalse<\/code><\/pre>\n\n\n\n
    2.2 \u901a\u8fc7 new Boolean()<\/code> \u6784\u9020\u51fd\u6570<\/strong><\/h4>\n\n\n\n
    \u867d\u7136\u53ef\u4ee5\u901a\u8fc7 new Boolean()<\/code> \u6765\u521b\u5efa\u4e00\u4e2a\u5e03\u5c14\u5bf9\u8c61\uff0c\u4f46\u8fd9\u901a\u5e38\u4e0d\u63a8\u8350\uff0c\u56e0\u4e3a\u5b83\u4f1a\u521b\u5efa\u4e00\u4e2a Boolean<\/code> \u7c7b\u578b\u7684\u5bf9\u8c61\uff0c\u800c\u4e0d\u662f\u7b80\u5355\u7684\u5e03\u5c14\u503c\u3002\u8fd9\u4f1a\u5f71\u54cd\u5e03\u5c14\u503c\u7684\u6bd4\u8f83\uff0c\u56e0\u4e3a\u5bf9\u8c61\u4e0e\u5e03\u5c14\u503c\u662f\u4e0d\u540c\u7684\u7c7b\u578b\u3002<\/p>\n\n\n\n
    let boolObj = new Boolean(true);\nconsole.log(boolObj);  \/\/ \u8f93\u51fa\uff1aBoolean { true }\nconsole.log(typeof boolObj);  \/\/ \u8f93\u51fa\uff1aobject<\/code><\/pre>\n\n\n\n
    \u6ce8\u610f\uff1a\u867d\u7136 boolObj<\/code> \u7684\u503c\u4e3a true<\/code>\uff0c\u4f46\u662f\u5b83\u662f\u4e00\u4e2a\u5bf9\u8c61\u800c\u4e0d\u662f\u57fa\u672c\u7c7b\u578b\u7684\u5e03\u5c14\u503c\u3002\u5982\u679c\u4f60\u5c06\u8fd9\u4e2a\u5bf9\u8c61\u4e0e true<\/code> \u6bd4\u8f83\u65f6\uff0c\u4f1a\u5f97\u5230 false<\/code>\uff0c\u56e0\u4e3a\u5b83\u4eec\u662f\u4e0d\u540c\u7684\u7c7b\u578b\u3002<\/p>\n\n\n\n
    console.log(boolObj == true);  \/\/ \u8f93\u51fa\uff1atrue\nconsole.log(boolObj === true);  \/\/ \u8f93\u51fa\uff1afalse<\/code><\/pre>\n\n\n\n
    2.3 \u901a\u8fc7\u7c7b\u578b\u8f6c\u6362\u521b\u5efa Boolean<\/strong><\/h4>\n\n\n\n
    JavaScript \u4e2d\u51e0\u4e4e\u6240\u6709\u7684\u503c\u90fd\u53ef\u4ee5\u901a\u8fc7\u7c7b\u578b\u8f6c\u6362\u8f6c\u4e3a\u5e03\u5c14\u503c\u3002\u5e38\u89c1\u7684\u6709\uff1a<\/p>\n\n\n\n
      \n
    • 0<\/code>\u3001null<\/code>\u3001undefined<\/code>\u3001NaN<\/code>\u3001''<\/code>\uff08\u7a7a\u5b57\u7b26\u4e32\uff09\u4f1a\u88ab\u8f6c\u6362\u4e3a false<\/code>\u3002<\/li>\n\n\n\n
    • \u5176\u4ed6\u4efb\u4f55\u503c\uff08\u5305\u62ec\u5bf9\u8c61\u3001\u6570\u7ec4\u3001\u975e\u7a7a\u5b57\u7b26\u4e32\u3001\u975e\u96f6\u6570\u5b57\u7b49\uff09\u90fd\u4f1a\u88ab\u8f6c\u6362\u4e3a true<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n
      console.log(Boolean(0));  \/\/ \u8f93\u51fa\uff1afalse\nconsole.log(Boolean(1));  \/\/ \u8f93\u51fa\uff1atrue\nconsole.log(Boolean(''));  \/\/ \u8f93\u51fa\uff1afalse\nconsole.log(Boolean('Hello'));  \/\/ \u8f93\u51fa\uff1atrue\nconsole.log(Boolean([]));  \/\/ \u8f93\u51fa\uff1atrue<\/code><\/pre>\n\n\n\n
      3. Boolean \u5bf9\u8c61\u7684\u65b9\u6cd5<\/strong><\/h3>\n\n\n\n
      Boolean<\/code> \u5bf9\u8c61\u672c\u8eab\u6ca1\u6709\u7279\u6b8a\u7684\u65b9\u6cd5\uff0c\u901a\u5e38\u6211\u4eec\u66f4\u5173\u5fc3\u7684\u662f\u5c06\u4e0d\u540c\u7c7b\u578b\u7684\u503c\u8f6c\u6362\u4e3a\u5e03\u5c14\u503c\u3002\u56e0\u6b64\uff0cBoolean<\/code> \u7c7b\u578b\u7684\u5e38\u89c1\u64cd\u4f5c\u65b9\u5f0f\u5305\u62ec\u901a\u8fc7 \u7c7b\u578b\u8f6c\u6362<\/strong> \u6216\u76f4\u63a5\u4f7f\u7528\u5e03\u5c14\u503c\u5224\u65ad\u3002<\/p>\n\n\n\n
      3.1 \u4f7f\u7528 Boolean()<\/code> \u51fd\u6570<\/strong><\/h4>\n\n\n\n
      Boolean()<\/code> \u51fd\u6570\u53ef\u4ee5\u5c06\u4efb\u4f55\u503c\u5f3a\u5236\u8f6c\u6362\u4e3a\u5e03\u5c14\u503c\u3002<\/p>\n\n\n\n
      console.log(Boolean(0));  \/\/ \u8f93\u51fa\uff1afalse\nconsole.log(Boolean(123));  \/\/ \u8f93\u51fa\uff1atrue\nconsole.log(Boolean('Hello'));  \/\/ \u8f93\u51fa\uff1atrue\nconsole.log(Boolean(null));  \/\/ \u8f93\u51fa\uff1afalse<\/code><\/pre>\n\n\n\n
      3.2 \u5728\u6761\u4ef6\u8bed\u53e5\u4e2d\u7684\u5e03\u5c14\u503c<\/strong><\/h4>\n\n\n\n
      \u5e03\u5c14\u503c\u5728 JavaScript \u4e2d\u5e38\u5e38\u7528\u4e8e\u6761\u4ef6\u5224\u65ad\u3002\u7531\u4e8e if<\/code> \u8bed\u53e5\u4f1a\u9690\u5f0f\u5730\u5c06\u6761\u4ef6\u8868\u8fbe\u5f0f\u8f6c\u6362\u4e3a\u5e03\u5c14\u503c\uff0c\u4ee5\u4e0b\u662f\u51e0\u79cd\u5e38\u89c1\u7684\u5e03\u5c14\u503c\u4f7f\u7528\u65b9\u5f0f\uff1a<\/p>\n\n\n\n
      let isValid = true;\n\nif (isValid) {\n  console.log(\"Valid!\");\n} else {\n  console.log(\"Invalid!\");\n}\n\nlet value = 0;\nif (value) {\n  console.log(\"This will not print\");\n} else {\n  console.log(\"This will print because 0 is falsy.\");\n}<\/code><\/pre>\n\n\n\n
      \u5728\u4e0a\u9762\u7684\u4f8b\u5b50\u4e2d\uff0cif (value)<\/code> \u4f1a\u5c06 value<\/code> \u81ea\u52a8\u8f6c\u6362\u4e3a\u5e03\u5c14\u503c\uff0c\u56e0\u6b64 0<\/code> \u4f1a\u88ab\u8ba4\u4e3a\u662f false<\/code>\uff0c\u5176\u4ed6\u4efb\u4f55\u975e 0<\/code> \u7684\u503c\u90fd\u4f1a\u88ab\u8ba4\u4e3a\u662f true<\/code>\u3002<\/p>\n\n\n\n
      4. \u5e03\u5c14\u503c\u5728\u903b\u8f91\u8fd0\u7b97\u4e2d\u7684\u4f7f\u7528<\/strong><\/h3>\n\n\n\n
      \u5e03\u5c14\u503c\u901a\u5e38\u7528\u4e8e \u903b\u8f91\u8fd0\u7b97<\/strong>\uff0c\u5982\u4e0e\uff08&&<\/code>\uff09\u3001\u6216\uff08||<\/code>\uff09\u548c\u975e\uff08!<\/code>\uff09\u64cd\u4f5c\u7b26\u3002<\/p>\n\n\n\n
      4.1 \u4e0e\uff08AND\uff09\u8fd0\u7b97\u7b26 &&<\/code><\/strong><\/h4>\n\n\n\n
        \n
      • \u5982\u679c\u5de6\u4fa7\u548c\u53f3\u4fa7\u7684\u503c\u90fd\u4e3a true<\/code>\uff0c\u7ed3\u679c\u4e3a true<\/code>\u3002<\/li>\n\n\n\n
      • \u5426\u5219\uff0c\u7ed3\u679c\u4e3a false<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n
        console.log(true && true);  \/\/ \u8f93\u51fa\uff1atrue\nconsole.log(true && false);  \/\/ \u8f93\u51fa\uff1afalse\nconsole.log(false && true);  \/\/ \u8f93\u51fa\uff1afalse\nconsole.log(false && false);  \/\/ \u8f93\u51fa\uff1afalse<\/code><\/pre>\n\n\n\n
        4.2 \u6216\uff08OR\uff09\u8fd0\u7b97\u7b26 ||<\/code><\/strong><\/h4>\n\n\n\n
          \n
        • \u5982\u679c\u5de6\u4fa7\u548c\u53f3\u4fa7\u7684\u503c\u4e2d\u81f3\u5c11\u6709\u4e00\u4e2a\u4e3a true<\/code>\uff0c\u7ed3\u679c\u4e3a true<\/code>\u3002<\/li>\n\n\n\n
        • \u5426\u5219\uff0c\u7ed3\u679c\u4e3a false<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n
          console.log(true || true);  \/\/ \u8f93\u51fa\uff1atrue\nconsole.log(true || false);  \/\/ \u8f93\u51fa\uff1atrue\nconsole.log(false || true);  \/\/ \u8f93\u51fa\uff1atrue\nconsole.log(false || false);  \/\/ \u8f93\u51fa\uff1afalse<\/code><\/pre>\n\n\n\n
          4.3 \u975e\uff08NOT\uff09\u8fd0\u7b97\u7b26 !<\/code><\/strong><\/h4>\n\n\n\n
            \n
          • \u5982\u679c\u5e03\u5c14\u503c\u4e3a true<\/code>\uff0c!<\/code> \u8fd0\u7b97\u7b26\u4f1a\u5c06\u5176\u8f6c\u6362\u4e3a false<\/code>\u3002<\/li>\n\n\n\n
          • \u5982\u679c\u5e03\u5c14\u503c\u4e3a false<\/code>\uff0c!<\/code> \u8fd0\u7b97\u7b26\u4f1a\u5c06\u5176\u8f6c\u6362\u4e3a true<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n
            console.log(!true);  \/\/ \u8f93\u51fa\uff1afalse\nconsole.log(!false);  \/\/ \u8f93\u51fa\uff1atrue<\/code><\/pre>\n\n\n\n
            5. \u5e03\u5c14\u503c\u5728\u5e38\u89c1\u8bed\u53e5\u4e2d\u7684\u5e94\u7528<\/strong><\/h3>\n\n\n\n
            5.1 \u4e09\u5143\u8fd0\u7b97\u7b26<\/strong><\/h4>\n\n\n\n
            \u4e09\u5143\u8fd0\u7b97\u7b26\u662f\u4e00\u79cd\u7b80\u6d01\u7684\u6761\u4ef6\u8bed\u53e5\uff0c\u6839\u636e\u5e03\u5c14\u503c\u5224\u65ad\u6761\u4ef6\u3002<\/p>\n\n\n\n
            let age = 18;\nlet canVote = (age >= 18) ? \"Yes, you can vote.\" : \"No, you cannot vote.\";\nconsole.log(canVote);  \/\/ \u8f93\u51fa\uff1aYes, you can vote.<\/code><\/pre>\n\n\n\n
            5.2 \u77ed\u8def\u8fd0\u7b97\u7b26<\/strong><\/h4>\n\n\n\n
              \n
            • &&<\/code> \u8fd0\u7b97\u7b26\u4f1a\u5728\u5de6\u4fa7\u4e3a false<\/code> \u65f6\u76f4\u63a5\u8fd4\u56de\u5de6\u4fa7\u7684\u503c\u3002<\/li>\n\n\n\n
            • ||<\/code> \u8fd0\u7b97\u7b26\u4f1a\u5728\u5de6\u4fa7\u4e3a true<\/code> \u65f6\u76f4\u63a5\u8fd4\u56de\u5de6\u4fa7\u7684\u503c\u3002<\/li>\n<\/ul>\n\n\n\n
              let isLoggedIn = true;\nlet user = isLoggedIn && \"John Doe\";  \/\/ \u53ea\u6709\u5728\u767b\u5f55\u72b6\u6001\u4e0b\uff0c\u624d\u4f1a\u5206\u914d\u7528\u6237\u540d\nconsole.log(user);  \/\/ \u8f93\u51fa\uff1aJohn Doe\n\nlet isLoggedOut = false;\nlet guestUser = isLoggedOut || \"Guest User\";  \/\/ \u672a\u767b\u5f55\u65f6\u663e\u793a\u6e38\u5ba2\nconsole.log(guestUser);  \/\/ \u8f93\u51fa\uff1aGuest User<\/code><\/pre>\n\n\n\n
              6. \u5b9e\u6218\u6848\u4f8b\uff1a\u5e03\u5c14\u503c\u7684\u5b9e\u9645\u5e94\u7528<\/strong><\/h3>\n\n\n\n
              6.1 \u5224\u65ad\u7528\u6237\u662f\u5426\u767b\u5f55<\/strong><\/h4>\n\n\n\n
              let isLoggedIn = true;\nlet access = isLoggedIn ? \"Access granted\" : \"Access denied\";\nconsole.log(access);  \/\/ \u8f93\u51fa\uff1aAccess granted<\/code><\/pre>\n\n\n\n
              6.2 \u8fc7\u6ee4\u5047\u503c<\/strong><\/h4>\n\n\n\n
              const data = [0, \"\", undefined, null, \"Hello\", 42, false];\nconst validData = data.filter(Boolean);\nconsole.log(validData);  \/\/ \u8f93\u51fa\uff1a[\"Hello\", 42]<\/code><\/pre>\n\n\n\n
              7. \u603b\u7ed3<\/strong><\/h3>\n\n\n\n
              \u5728 JavaScript \u4e2d\uff0c\u5e03\u5c14\u503c (true<\/code> \u548c false<\/code>) \u662f\u6700\u57fa\u672c\u7684\u903b\u8f91\u6570\u636e\u7c7b\u578b\u3002\u5e03\u5c14\u503c\u5e7f\u6cdb\u5e94\u7528\u4e8e\u6761\u4ef6\u8bed\u53e5\u3001\u903b\u8f91\u8fd0\u7b97\u548c\u5404\u79cd\u5224\u65ad\u4e2d\u3002\u5c3d\u7ba1 Boolean<\/code> \u5bf9\u8c61\u53ef\u4ee5\u521b\u5efa\uff0c\u4f46\u901a\u5e38\u4f7f\u7528\u57fa\u672c\u7c7b\u578b\u5e03\u5c14\u503c\u4f1a\u66f4\u7b80\u6d01\u4e14\u66f4\u5177\u53ef\u8bfb\u6027\u3002\u638c\u63e1\u5e03\u5c14\u503c\u7684\u7528\u6cd5\u5bf9\u4e8e\u7f16\u5199\u6e05\u6670\u3001\u6613\u61c2\u7684\u903b\u8f91\u975e\u5e38\u91cd\u8981\u3002<\/p>\n\n\n\n
              \u66f4\u591a\u8be6\u7ec6\u5185\u5bb9\u8bf7\u5173\u6ce8\u5176\u4ed6\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
              \u5728 JavaScript \u4e2d\uff0cBoolean\uff08\u5e03\u5c14\uff09 \u662f\u4e00\u79cd\u8868\u793a\u903b\u8f91\u503c\u7684\u6570\u636e\u7c7b\u578b\uff0c\u53ea\u6709\u4e24\u4e2a\u53ef\u80fd\u7684\u503c\uff1atrue  […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[46],"tags":[],"class_list":["post-2135","post","type-post","status-publish","format-standard","hentry","category-javascript"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2135","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=2135"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2135\/revisions"}],"predecessor-version":[{"id":2136,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2135\/revisions\/2136"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=2135"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=2135"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=2135"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}