blocks|key|21821|text|您可以使用纯Javascript来实现此目的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|21822|var+test+=+true;
if+(typeof+test+===+'boolean')
+++console.log('test+is+a+boolean!');|code-block|syntax|javascript|21823|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>You can use pure Javascript to achieve this:</p>

<pre><code>var test = true;
if (typeof test === 'boolean')
   console.log('test is a boolean!');
</code></pre>


blocks|key|21865|text|在JavaScript中检查变量类型最可靠的方法是the+following|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|21866|var+toType+=+function(obj)+{
++return+({}).toString.call(obj).match(/\s([a-zA-Z]%2B)/)[1].toLowerCase()
}
toType(new+Boolean(true))+//+returns+"boolean"
toType(true);+//+returns+"boolean"|code-block|syntax|javascript|21867|造成这种复杂性的原因是typeof+true返回"boolean"，而typeof+new+Boolean(true)返回"object"。|style|CODE|21868|entityMap|0|LINK|mutability|MUTABLE|url|http://www.2ality.com/2011/11/improving-typeof.html^0|P|D|0|0|0|B|B|O|9|Z|O|1P|8|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@$A|V|B|W|1|X]]|C|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|Z|8|@$A|10|B|11|K|L]|$A|12|B|13|K|L]|$A|14|B|15|K|L]|$A|16|B|17|K|L]]|9|@]|C|$]]|$1|M|3|-4|5|6|7|18|8|@]|9|@]|C|$]]]|N|$O|$5|P|Q|R|C|$S|T]]]]

<p>The most reliable way to check type of a variable in JavaScript is <a href="http://www.2ality.com/2011/11/improving-typeof.html" rel="nofollow">the following</a>:</p>

<pre><code>var toType = function(obj) {
  return ({}).toString.call(obj).match(/\s([a-zA-Z]+)/)[1].toLowerCase()
}
toType(new Boolean(true)) // returns "boolean"
toType(true); // returns "boolean"
</code></pre>

<p>The reason for this complication is that <code>typeof true</code> returns <code>"boolean"</code> while <code>typeof new Boolean(true)</code> returns <code>"object"</code>.</p>


blocks|key|4529525|text|如果您只想检查原始值|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4529526|typeof+variable+===+'boolean'|code-block|syntax|javascript|4529527|如果出于某种奇怪的原因，您使用构造函数创建了布尔值，那么这些布尔值实际上并不是布尔值，而是包含原始布尔值的对象，检查原始布尔值和使用new+Boolean创建的对象的一种方法是：|offset|length|style|CODE|4529528|function+checkBool(bool)+{
++++return+typeof+bool+===+'boolean'+%7C%7C+
+++++++++++(typeof+bool+===+'object'+&&+
++++++++++++bool+!==+null++++++++++++&&
+++++++++++typeof+bool.valueOf()+===+'boolean');
}|4529529|​|4529530|function+checkBool(bool)+{
++++return+typeof+bool+===+'boolean'+%7C%7C+
+++++++++++(typeof+bool+===+'object'+&&+
++++++++++++bool+!==+null++++++++++++&&
+++++++++++typeof+bool.valueOf()+===+'boolean');
}

console.log(+checkBool(+'string'++++++++++));+//+false,+string
console.log(+checkBool(+{test:+'this'}++++));+//+false,+object
console.log(+checkBool(+null++++++++++++++));+//+false,+null
console.log(+checkBool(+undefined+++++++++));+//+false,+undefined
console.log(+checkBool(+new+Boolean(true)+));+//+true
console.log(+checkBool(+new+Boolean()+++++));+//+true
console.log(+checkBool(+true++++++++++++++));+//+true
console.log(+checkBool(+false+++++++++++++));+//+true|4529531|4529532|entityMap^0|0|0|1U|B|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|V|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|W|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|X|8|@$I|Y|J|Z|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|10|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|11|8|@]|9|@]|A|$]]|$1|Q|3|R|5|D|7|12|8|@]|9|@]|A|$E|F]]|$1|S|3|P|5|6|7|13|8|@]|9|@]|A|$]]|$1|T|3|-4|5|6|7|14|8|@]|9|@]|A|$]]]|U|$]]

<p>If you just want to check for a primitive value</p>

<pre><code>typeof variable === 'boolean'
</code></pre>

<p>If for some strange reason you have booleans created with the constructor, those aren't really booleans but objects containing a primitive boolean value, and one way to check for both primitive booleans and objects created with <code>new Boolean</code> is to do :</p>

<pre><code>function checkBool(bool) {
    return typeof bool === 'boolean' || 
           (typeof bool === 'object' &amp;&amp; 
            bool !== null            &amp;&amp;
           typeof bool.valueOf() === 'boolean');
}
</code></pre>

<p><div class="snippet" data-lang="js" data-hide="true" data-console="true" data-babel="false">
<div class="snippet-code snippet-currently-hidden">
<pre class="snippet-code-js lang-js prettyprint-override"><code>function checkBool(bool) {
    return typeof bool === 'boolean' || 
           (typeof bool === 'object' &amp;&amp; 
            bool !== null            &amp;&amp;
           typeof bool.valueOf() === 'boolean');
}

console.log( checkBool( 'string'          )); // false, string
console.log( checkBool( {test: 'this'}    )); // false, object
console.log( checkBool( null              )); // false, null
console.log( checkBool( undefined         )); // false, undefined
console.log( checkBool( new Boolean(true) )); // true
console.log( checkBool( new Boolean()     )); // true
console.log( checkBool( true              )); // true
console.log( checkBool( false             )); // true</code></pre>
</div>
</div>
</p>


blocks|key|21961|text|我使用Lodash：isBoolean检查传入的变量是原始布尔型还是布尔型包装器对象，因此考虑了所有情况。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|21962|entityMap|0|LINK|mutability|MUTABLE|url|https://lodash.com/docs/4.16.6#isBoolean^0|A|9|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

<p>I would go with Lodash: <a href="https://lodash.com/docs/4.16.6#isBoolean" rel="nofollow noreferrer">isBoolean</a> checks whether the passed-in variable is either primitive boolean or Boolean wrapper object and so accounts for all cases.</p>


blocks|key|21977|text|您可以创建一个函数来检查typeof中的参数。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|21978|function+isBoolean(value)+{
++return+typeof+value+===+"boolean";
}|code-block|syntax|javascript|21979|entityMap^0|C|6|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

<p>You can create a function that checks the <code>typeof</code> for an argument.</p>

<pre><code>function isBoolean(value) {
  return typeof value === "boolean";
}
</code></pre>


blocks|key|22008|text|如果您希望您的函数也可以验证布尔对象，最有效的解决方案必须是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|22009|function+isBoolean(val)+{
++return+val+===+false+%7C%7C+val+===+true+%7C%7C+val+instanceof+Boolean;
}|code-block|syntax|javascript|22010|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>If you want your function can validate boolean objects too, the most efficient solution must be:</p>

<pre><code>function isBoolean(val) {
  return val === false || val === true || val instanceof Boolean;
}
</code></pre>


blocks|key|4529673|text|有时我们需要一种单一的方法来检查它。typeof+not+working+for+date等，所以我让它变得很容易|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4529674|Date.prototype.getType()+{+return+"date";+}|code-block|syntax|javascript|4529675|此外，对于Number、String、Boolean等，我们通常需要以单一的方式检查类型……|offset|length|style|CODE|4529676|entityMap^0|0|0|5|6|C|6|J|7|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]|$I|T|J|U|K|L]|$I|V|J|W|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|X|8|@]|9|@]|A|$]]]|N|$]]

<p>Sometimes we need a single way to check it. typeof not working for date etc. So I made it easy by</p>

<pre><code>Date.prototype.getType() { return "date"; }
</code></pre>

<p>Also for <code>Number</code>, <code>String</code>, <code>Boolean</code> etc. we often need to check the type in a single way...</p>


blocks|key|4529693|text|if(['true',+'yes',+'1'].includes(single_value))+{
++++return++true;+++
}
else+if(['false',+'no',+'0'].includes(single_value))+{
++++return++false;++
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|4529694|如果你有一个字符串|unstyled|4529695|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>if(['true', 'yes', '1'].includes(single_value)) {
    return  true;   
}
else if(['false', 'no', '0'].includes(single_value)) {
    return  false;  
}
</code></pre>

<p>if you have a string</p>


blocks|key|4529725|text|在nodejs中，通过使用node-boolify，我们可以使用isBoolean()；|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|4529726|++++++++var+isBoolean+=+require('node-boolify').isBoolean;
++++++++isBoolean(true);+//true
++++++++isBoolean('true');+//true
++++++++isBoolean('TRUE');+//false
++++++++isBoolean(1);+//true
++++++++isBoolean(2);+//false
++++++++isBoolean(false);+//true
++++++++isBoolean('false');+//true
++++++++isBoolean('FALSE');+//false
++++++++isBoolean(0);+//true
++++++++isBoolean(null);+//false
++++++++isBoolean(undefined);+//false
++++++++isBoolean();+//false
++++++++isBoolean('');+//false|code-block|syntax|javascript|4529727|entityMap|0|LINK|mutability|MUTABLE|url|https://www.npmjs.com/package/node-boolify^0|D|C|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

<p>In nodejs by using <a href="https://www.npmjs.com/package/node-boolify" rel="nofollow noreferrer">node-boolify</a> we can use isBoolean();</p>

<pre><code>        var isBoolean = require('node-boolify').isBoolean;
        isBoolean(true); //true
        isBoolean('true'); //true
        isBoolean('TRUE'); //false
        isBoolean(1); //true
        isBoolean(2); //false
        isBoolean(false); //true
        isBoolean('false'); //true
        isBoolean('FALSE'); //false
        isBoolean(0); //true
        isBoolean(null); //false
        isBoolean(undefined); //false
        isBoolean(); //false
        isBoolean(''); //false
</code></pre>


blocks|key|4529747|text|使用es2015箭头函数再做一次判断|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4529748|const+isBoolean+=+val+=>+typeof+val+===+'boolean';|code-block|syntax|javascript|4529749|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>One more decision with es2015 arrow function</p>

<pre><code>const isBoolean = val =&gt; typeof val === 'boolean';
</code></pre>


blocks|key|4529759|text|​|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4529760|const+isBoolean+=+(val)+=>+{
++const+boolValuesRegex+=+/true%7Cfalse/;+//+Add+other+/true%7Cfalse%7C1%7C0%7Con%7Coff/
++if+(val+===+undefined+%7C%7C+val+===+null)+return+false;
++return+boolValuesRegex.test(val.toString().toLowerCase());
}

const+values+=+[true,+false,+'true',+'false',+'TRUE',+'FALSE',+'sampletext',+1,+undefined,+null,+(()+=>+{}),+{},+[]];
document.body.innerHTML+=+values.map(x+=>+`${x}+-+${isBoolean(x)}`).join('</br>');|code-block|syntax|javascript|4529761|4529762|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|K|8|@]|9|@]|A|$E|F]]|$1|G|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|M|8|@]|9|@]|A|$]]]|I|$]]

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>const isBoolean = (val) =&gt; {
  const boolValuesRegex = /true|false/; // Add other /true|false|1|0|on|off/
  if (val === undefined || val === null) return false;
  return boolValuesRegex.test(val.toString().toLowerCase());
}

const values = [true, false, 'true', 'false', 'TRUE', 'FALSE', 'sampletext', 1, undefined, null, (() =&gt; {}), {}, []];
document.body.innerHTML = values.map(x =&gt; `${x} - ${isBoolean(x)}`).join('&lt;/br&gt;');</code></pre>
</div>
</div>
</p>


<p>How can I check if a variable's type is of type Boolean?</p>

<p>I mean, there are some alternatives such as:</p>

<pre><code>if(jQuery.type(new Boolean()) === jQuery.type(variable))
      //Do something..
</code></pre>

<p>But that doesn't seem pretty to me.</p>

<p>Is there a cleaner way to achieve this?</p>


How to check if type is Boolean

jQuery

如何检查变量的类型是否为Boolean类型？我的意思是，有一些替代方案，例如：if(jQuery.type(new Boolean()) === jQuery.type(variable))      //Do something..但这对我来说并不是很好。有没有更干净的方法来实现这一点？

问如何检查type是否为Boolean
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