blocks|key|330749|text|下面是交换两个变量的值的一行代码。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|330750|给定变量a和b|offset|length|style|CODE|330751|b+=+[a,+a+=+b][0];|code-block|syntax|javascript|330752|演示如下：|330753|​|330754|var+a=1,
++++b=2,
++++output=document.getElementById('output');

output.innerHTML="<p>Original:+"%2Ba%2B",+"%2Bb%2B"</p>";

b+=+[a,+a+=+b][0];

output.innerHTML%2B="<p>Swapped:+"%2Ba%2B",+"%2Bb%2B"</p>";|330755|<div+id="output"></div>|330756|330757|entityMap^0|0|4|1|6|1|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|X|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Y|8|@$D|Z|E|10|F|G]|$D|11|E|12|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|13|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|14|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|15|8|@]|9|@]|A|$]]|$1|Q|3|R|5|J|7|16|8|@]|9|@]|A|$K|L]]|$1|S|3|T|5|J|7|17|8|@]|9|@]|A|$K|L]]|$1|U|3|P|5|6|7|18|8|@]|9|@]|A|$]]|$1|V|3|-4|5|6|7|19|8|@]|9|@]|A|$]]]|W|$]]

<p>Here's a one-liner to swap the values of two variables.<br>
Given variables <code>a</code> and <code>b</code>:</p>

<pre><code>b = [a, a = b][0];
</code></pre>

<p>Demonstration below:</p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="false" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>var a=1,
    b=2,
    output=document.getElementById('output');

output.innerHTML="&lt;p&gt;Original: "+a+", "+b+"&lt;/p&gt;";

b = [a, a = b][0];

output.innerHTML+="&lt;p&gt;Swapped: "+a+", "+b+"&lt;/p&gt;";</code></pre>
<pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div id="output"&gt;&lt;/div&gt;</code></pre>
</div>
</div>
</p>


blocks|key|113494|text|ES6+(火狐和Chrome已经支持它(解构赋值数组匹配))：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|113495|​|113496|let+a+=+5,+b+=+6;
[a,+b]+=+[b,+a];
console.log(`${a}+${b}`);|code-block|syntax|javascript|113497|113498|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|N|8|@]|9|@]|A|$G|H]]|$1|I|3|C|5|6|7|O|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|P|8|@]|9|@]|A|$]]]|K|$]]

<p>ES6 (Firefox and Chrome already support it (Destructuring Assignment
Array Matching)):</p>

<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>let a = 5, b = 6;
[a, b] = [b, a];
console.log(`${a} ${b}`);</code></pre>
</div>
</div>
</p>


blocks|key|113575|text|从ES6开始，您还可以更优雅地交换变量：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|113576|var+a+=+1,
++++b+=+2;

[a,+b]+=+[b,+a];

console.log('a:',+a,+'b:',+b);+//+a:+2+b:+1|code-block|syntax|javascript|113577|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>Since ES6, you can also swap variables more elegantly:</p>



<pre class="lang-js prettyprint-override"><code>var a = 1,
    b = 2;

[a, b] = [b, a];

console.log('a:', a, 'b:', b); // a: 2 b: 1
</code></pre>


blocks|key|113592|text|现在，您终于可以执行以下操作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|113593|​|113594|let+a+=+5;
let+b+=+10;

[a,+b]+=+[b,+a];+//+ES6

console.log(a,+b);|code-block|syntax|javascript|113595|113596|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|N|8|@]|9|@]|A|$G|H]]|$1|I|3|C|5|6|7|O|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|P|8|@]|9|@]|A|$]]]|K|$]]

<p>You can now finally do:</p>
<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>let a = 5;
let b = 10;

[a, b] = [b, a]; // ES6

console.log(a, b);</code></pre>
</div>
</div>
</p>


blocks|key|113359|text|因为你的问题很珍贵，“只有这个变量，没有任何对象"，所以答案也很珍贵：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|113360|变量a=+1，b=2|113361|a=a%2Bb;
b=a-b;
a=a-b;|code-block|syntax|javascript|113362|这是个骗局|113363|正如罗德里戈·阿西斯所说，它“可以更短”|113364|+b=a%2B(a=b)-b;|113365|演示：http://jsfiddle.net/abdennour/2jJQ2/|offset|length|113366|entityMap|0|LINK|mutability|MUTABLE|url|http://jsfiddle.net/abdennour/2jJQ2/^0|0|0|0|0|0|0|3|10|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|11|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|12|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|13|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|14|8|@]|9|@]|A|$]]|$1|M|3|N|5|F|7|15|8|@]|9|@]|A|$G|H]]|$1|O|3|P|5|6|7|16|8|@]|9|@$Q|17|R|18|1|19]]|A|$]]|$1|S|3|-4|5|6|7|1A|8|@]|9|@]|A|$]]]|T|$U|$5|V|W|X|A|$Y|Z]]]]

<p>As your question was precious "Only this variables, not any objects. ", the answer will be also precious:</p>

<p>var a = 1,
        b = 2</p>

<pre><code>a=a+b;
b=a-b;
a=a-b;
</code></pre>

<p>it's a trick<br><br>
And as  Rodrigo Assis said, it "can be shorter "</p>

<pre><code> b=a+(a=b)-b;
</code></pre>

<p>Demo:
<a href="http://jsfiddle.net/abdennour/2jJQ2/">http://jsfiddle.net/abdennour/2jJQ2/</a></p>


blocks|key|113406|text|我们怎么会错过这些经典的单行程序呢|type|unstyled|depth|inlineStyleRanges|entityRanges|data|113407|var+a+=+1,+b+=+2
a+=+({a:b,+_:(b=a)}).a;|code-block|syntax|javascript|113408|和|113409|var+a+=+1,+b+=+2
a+=+(_=b,b=a,_);|113410|最后一个公开了全局变量'_‘，但这无关紧要，因为典型的javascript约定是将其用作’无关‘变量。|113411|entityMap^0|0|0|0|0|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]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

<p>How could we miss these classic oneliners</p>

<pre><code>var a = 1, b = 2
a = ({a:b, _:(b=a)}).a;
</code></pre>

<p>And</p>

<pre><code>var a = 1, b = 2
a = (_=b,b=a,_);
</code></pre>

<p>The last one exposes global variable '_' but that should not matter as typical javascript convention is to use it as 'dont care' variable.</p>


blocks|key|113430|text|我在这里看到了一种编程奥林匹克竞赛。另一个棘手的单行解决方案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|113431|b+=+(function(){+a=b;+return+arguments[0];+})(a);|code-block|syntax|javascript|113432|小提琴：http://jsfiddle.net/cherniv/4q226/|offset|length|113433|entityMap|0|LINK|mutability|MUTABLE|url|http://jsfiddle.net/cherniv/4q226/^0|0|0|4|Y|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@$I|V|J|W|1|X]]|A|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|R]]]]

<p>I see kind of programming olympiad here. One more tricky one-line solution:</p>

<pre><code>b = (function(){ a=b; return arguments[0]; })(a);
</code></pre>

<p>Fiddle: <a href="http://jsfiddle.net/cherniv/4q226/" rel="nofollow">http://jsfiddle.net/cherniv/4q226/</a></p>


blocks|key|330892|text|单行交换|type|unstyled|depth|inlineStyleRanges|entityRanges|data|330893|a+=+a%5Eb%5E(b%5E=(a%5Eb));|code-block|syntax|javascript|330894|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>Single line swapping </p>

<pre><code>a = a^b^(b^=(a^b));
</code></pre>


blocks|key|331008|text|var+a+=+5;
var+b+=+10;

b+=+[a,+a+=+b][0];
//or
b+=+[a,+a+=+b];
b+=+b[0];

//or
b+=+[a,+b];
a+=+b[1];
b+=+b[0];


alert("a="+%2B+a+%2B+','+%2B+"b="+%2B+b);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|331009|删除或注释2//或，并使用一组代码运行|unstyled|331010|http://jsfiddle.net/USdv8/57/|offset|length|331011|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|0|T|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|S|8|@]|9|@]|A|$]]|$1|G|3|H|5|F|7|T|8|@]|9|@$I|U|J|V|1|W]]|A|$]]|$1|K|3|-4|5|F|7|X|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|H]]]]

<pre><code>var a = 5;
var b = 10;

b = [a, a = b][0];
//or
b = [a, a = b];
b = b[0];

//or
b = [a, b];
a = b[1];
b = b[0];


alert("a=" + a + ',' + "b=" + b);
</code></pre>

<p>remove or comment the 2 //or's and run with the one set of code</p>

<p><a href="http://jsfiddle.net/USdv8/57/" rel="nofollow">http://jsfiddle.net/USdv8/57/</a></p>


blocks|key|330975|text|我们可以像这样交换var：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|330976|var+val1+=++117,
++++val2+=+327;

val2+=+val1-val2;+
console.log(val2);
val1+=+val1-val2;
console.log(val1);
val2+=+val1%2Bval2;
console.log(val2);|code-block|syntax|javascript|330977|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>We are able to swap var like this : </p>

<pre><code>var val1 =  117,
    val2 = 327;

val2 = val1-val2; 
console.log(val2);
val1 = val1-val2;
console.log(val1);
val2 = val1+val2;
console.log(val2);
</code></pre>


blocks|key|113681|text|直到ES5，要交换两个数字，您必须创建一个temp变量，然后交换它。但在ES6中，使用数组解构很容易交换两个数字。请参见示例。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|113682|let+x,y;
[x,y]=[2,3];
console.log(x,y);++++++//+return+2,3

[x,y]=[y,x];
console.log(x,y);++++++//+return+3,2|code-block|syntax|javascript|113683|Know+more+about+JavaScript+ES6+destructuring|offset|length|113684|entityMap|0|LINK|mutability|MUTABLE|url|https://tutorial.techaltum.com/js-destructuring.html#swap^0|0|0|0|18|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@$I|V|J|W|1|X]]|A|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|R]]]]

<p>Till ES5, to swap two numbers, you have to create a temp variable and then swap it.
But in ES6, its very easy to swap two numbers using array destructuring. See example.</p>
<pre><code>let x,y;
[x,y]=[2,3];
console.log(x,y);      // return 2,3

[x,y]=[y,x];
console.log(x,y);      // return 3,2
</code></pre>
<p><a href="https://tutorial.techaltum.com/js-destructuring.html#swap" rel="nofollow noreferrer">Know more about JavaScript ES6 destructuring</a></p>


blocks|key|113633|text|let+a+=+2,+b+=+4;
[b,+a]+=+[a,+b];|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|113634|一种更冗长的方法是|unstyled|113635|let+a+=+2,+b+=+4;
a+=+[a,+b];
b+=+a[0];
a+=+a[1];|113636|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|L|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$B|C]]|$1|I|3|-4|5|F|7|N|8|@]|9|@]|A|$]]]|J|$]]

<pre><code>let a = 2, b = 4;
[b, a] = [a, b];
</code></pre>

<p>a more verbose approach would be</p>

<pre><code>let a = 2, b = 4;
a = [a, b];
b = a[0];
a = a[1];
</code></pre>


blocks|key|113711|text|因为我听说这个方法运行较慢：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|113712|b+=+[a,+a+=+b][0];|code-block|syntax|javascript|113713|如果您计划将var存储在一个对象(或数组)中，则此函数应该可以工作：|113714|function+swapVars(obj,+var1,+var2){
++++let+temp+=+obj[var1];
++++obj[var1]+=+obj[var2];
++++obj[var2]+=+temp;
}|113715|用法：|113716|let+test+=+{a:+'test+1',+b:+'test+2'};

console.log(test);+//output:+{a:+'test+1',+b:+'test+2'}

swapVars(test,+'a',+'b');

console.log(test);+//output:+{a:+'test+2',+b:+'test+1'}|113717|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

<p>Because I hear this method runs slower:</p>

<pre><code>b = [a, a = b][0];
</code></pre>

<p>If you plan on storing your vars in an object (or array), this function should work:</p>

<pre><code>function swapVars(obj, var1, var2){
    let temp = obj[var1];
    obj[var1] = obj[var2];
    obj[var2] = temp;
}
</code></pre>

<p>Usage:</p>

<pre><code>let test = {a: 'test 1', b: 'test 2'};

console.log(test); //output: {a: 'test 1', b: 'test 2'}

swapVars(test, 'a', 'b');

console.log(test); //output: {a: 'test 2', b: 'test 1'}
</code></pre>


blocks|key|113748|text|我们可以使用IIFE来交换两个值，而不需要额外的参数|type|unstyled|depth|inlineStyleRanges|entityRanges|data|113749|​|113750|var+a+=+5,+b+=8;
b+=+(function(a){+
++++return+a+
}(a,+a=b));

document.write("a:+"+%2B+a%2B+"++b:++"%2B+b);|code-block|syntax|javascript|113751|113752|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|N|8|@]|9|@]|A|$G|H]]|$1|I|3|C|5|6|7|O|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|P|8|@]|9|@]|A|$]]]|K|$]]

<p>We can use the IIFE to swap two value without extra parameter</p>

<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>var a = 5, b =8;
b = (function(a){ 
    return a 
}(a, a=b));

document.write("a: " + a+ "  b:  "+ b);</code></pre>
</div>
</div>
</p>


blocks|key|113819|text|虽然之前给出了相同的答案，但这里有一个png来描述它。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|113820|最简单的形式：|113821|​|113822|📷|atomic|offset|length|113823|113824|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/33795e3ab6ac37819dfc39486e2c8f56.png|imageAlt^0|0|0|0|0|1|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|X|8|@]|9|@$I|Y|J|Z|1|10]]|A|$]]|$1|K|3|E|5|6|7|11|8|@]|9|@]|A|$]]|$1|L|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|M|$N|$5|O|P|Q|A|$R|S|T|-4]]]]

<p>Although the same answer is given previously, but here is a png to describe it.</p>
<p>Simplest form possible:</p>
<p><a href="https://i.stack.imgur.com/6dLlV.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/6dLlV.png" alt="enter image description here" /></a></p>


<p>I have this two variables:</p>

<pre><code>var a = 1,
    b = 2;
</code></pre>

<p>My question is how to swap them? Only this variables, not any objects.</p>


How to swap two variables in JavaScript

我有这两个变量：var a = 1,    b = 2;我的问题是如何交换它们？只有这个变量，没有任何对象。

问如何在JavaScript中交换两个变量
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回答 15

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问如何在JavaScript中交换两个变量
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