blocks|key|4407845|text|假设@DominicTobias是正确的，你可以使用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4407846|​|4407847|console.log(+
++++%2Bprompt("Enter+a+value").split("").reverse().join("")+
)|code-block|syntax|javascript|4407848|4407849|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>Assuming @DominicTobias is correct, you can use this:</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>console.log( 
    +prompt("Enter a value").split("").reverse().join("") 
)</code></pre>
</div>
</div>
</p>


blocks|key|4408007|text|或者，作为一行程序(+x包含要反转的整数)：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4408008|revX=x.toFixed(0).split('').reverse().join('')-0;|code-block|syntax|javascript|4408009|数字将被分成单独的数字，颠倒过来，然后重新组合成一个字符串。然后，-0再次将其转换为数字。|4408010|entityMap^0|B|1|0|0|X|2|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|M|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|N|$]]

<p>Or, as a one-liner ( <code>x</code> contains the integer number to be inversed):</p>

<pre><code>revX=x.toFixed(0).split('').reverse().join('')-0;
</code></pre>

<p>The number will be separated into its individual digits, reversed and then reassembled again into a string. The <code>-0</code> then converts it into a number again.</p>


blocks|key|4408248|text|这是我的解决方案，没有预定义函数的纯JS。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4408249|++++function+reverseNum(number)+{
++var+result+=+0,
++++counter+=+0;
++for+(i+=+number;+i+>=+1;+i+=+i+/+10+-+(i+%25+10)+*+0.1)+{
++++counter+=+i+%25+10;
++++result+=+result+*+10+%2B+counter;
++}
++return+result;
}

console.log(reverseNum(547793));|code-block|syntax|javascript|4408250|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>This is my solution, pure JS without predefined functions.</p>
<pre><code>    function reverseNum(number) {
  var result = 0,
    counter = 0;
  for (i = number; i &gt;= 1; i = i / 10 - (i % 10) * 0.1) {
    counter = i % 10;
    result = result * 10 + counter;
  }
  return result;
}

console.log(reverseNum(547793));
</code></pre>


blocks|key|4407886|text|首先，我认为你没有使用数组来存储数字。您正在使用java脚本变量。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4407887|试试这段代码，看看它是否能正常工作。|4407888|var+a+=+prompt("Enter+a+value");
var+z+=+a;
var+reverse+=+0;
while(z+>+0)
{
++++var+digit+=+z+%25+10;
++++reverse+=+(reverse+*+10)+%2B+digit;
++++z+=+parseInt(z+/+10);
}
alert("reverse+=+"+%2B+reverse);|code-block|syntax|javascript|4407889|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

<p>Firstly, I don't think you are using an array to store the number. You are using a java script variable.</p>

<p>Try out this code and see if it works.</p>

<pre><code>var a = prompt("Enter a value");
var z = a;
var reverse = 0;
while(z &gt; 0)
{
    var digit = z % 10;
    reverse = (reverse * 10) + digit;
    z = parseInt(z / 10);
}
alert("reverse = " + reverse);
</code></pre>


blocks|key|4407927|text|解释|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4407928|使用JavaScript+reverse()数组方法可以颠倒数组元素的顺序。|offset|length|style|CODE|4407929|代码|4407930|​|4407931|var+a+=+prompt("Enter+a+value");
var+arr+=+[];

for+(var+i+=+0;+i+<+a.length;+i%2B%2B)+{
++++arr[i]+=+a.charAt(i);
}
arr.reverse();
alert(arr);|code-block|syntax|javascript|4407932|4407933|entityMap^0|0|D|9|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|T|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|U|8|@$D|V|E|W|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|X|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|Y|8|@]|9|@]|A|$]]|$1|L|3|M|5|N|7|Z|8|@]|9|@]|A|$O|P]]|$1|Q|3|K|5|6|7|10|8|@]|9|@]|A|$]]|$1|R|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|S|$]]

<h2>Explanation</h2>
<p>Using the JavaScript <code>reverse()</code> array method you can reverse the order of the array elements.</p>
<h2>Code</h2>
<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 = prompt("Enter a value");
var arr = [];

for (var i = 0; i &lt; a.length; i++) {
    arr[i] = a.charAt(i);
}
arr.reverse();
alert(arr);</code></pre>
</div>
</div>
</p>


blocks|key|4408134|text|我的反转字符串的解决方案是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4408135|var+text+=+""
var+i+=+0
var+array+=+["1",+"2",+"3"]
var+number+=+array.length
var+arrayFinal+=+[]

for+(i+=+0;+i+<+array.length;+i%2B%2B)+{
++++text+=+array[number+-+1]
++++arrayFinal.push(text)
++++text+=+""
++++number+=+number+-+1
}

console.log(arrayFinal)|code-block|syntax|javascript|4408136|希望这能有所帮助！|4408137|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

<p>My solution to reverse a string:</p>

<pre><code>var text = ""
var i = 0
var array = ["1", "2", "3"]
var number = array.length
var arrayFinal = []

for (i = 0; i &lt; array.length; i++) {
    text = array[number - 1]
    arrayFinal.push(text)
    text = ""
    number = number - 1
}

console.log(arrayFinal)
</code></pre>

<p>Hopes This Helps!</p>


blocks|key|4408222|text|假设您可能希望将其反转为一个真实的数字，而不是一个字符串，请尝试以下操作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4408223|function+reverseNumber(num){
++++num+=+num+%2B+'';
++++++++let+reversedText+=+num.split('').reverse().join('');
++++++++let+reversedNumber+=+parseInt(reversedText,+10);
++++console.log("reversed+number:+",+reversedNumber);
++++++++return+reversedNumber;
++}|code-block|syntax|javascript|4408224|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>Assuming you may want to reverse it as a true number and not a string try the following:</p>

<pre><code>function reverseNumber(num){
    num = num + '';
        let reversedText = num.split('').reverse().join('');
        let reversedNumber = parseInt(reversedText, 10);
    console.log("reversed number: ", reversedNumber);
        return reversedNumber;
  }
</code></pre>


blocks|key|4408272|text|使用JavaScript+reverse()和Math.sign()可以反转正数和负数。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4408273|var+enteredNum+=+prompt("Enter+integer");

function+reverseInteger(enteredNum)+{
++++const+reveredNumber+=+enteredNum.toString().split('').reverse().join('');
++++return+parseInt(reveredNumber)*Math.sign(enteredNum);
}

alert(reverseInteger(enteredNum));|code-block|syntax|javascript|4408274|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>Using JavaScript reverse() and Math.sign() you can reverse a number both positive and negative numbers.</p>

<pre><code>var enteredNum = prompt("Enter integer");

function reverseInteger(enteredNum) {
    const reveredNumber = enteredNum.toString().split('').reverse().join('');
    return parseInt(reveredNumber)*Math.sign(enteredNum);
}

alert(reverseInteger(enteredNum));
</code></pre>


blocks|key|4408145|text|在论文中应用倒数逻辑并尝试，你必须关心除法，因为它给出了浮点值，这就是为什么我们必须使用parseInt()。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4408146|<head>
<script>
++++function+palindrome()
++++{
++++++++var+a+=+document.getElementById('str').value;
++++++++var+r=0+,t=0;
++++++++while(a>0){
++++++++++++r=a%2510;
++++++++++++t=t*10%2Br;
++++++++++++a=parseInt(a/10);
++++++++}
++++++++
++++++++document.write(t);
++++++++
++++}
++++</script>

</head>

<body>
<form>
++++<input+type="text"+id="str"/>
++++<input+type="submit"+onClick="palindrome()"+/>
<form>
</body>
</html>|code-block|syntax|javascript|4408147|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>Apply Logic of reversing number in paper and try,and you have to care about dividing because it gives float values thats why we have to use parseInt().</p>
<pre><code>&lt;head&gt;
&lt;script&gt;
    function palindrome()
    {
        var a = document.getElementById('str').value;
        var r=0 ,t=0;
        while(a&gt;0){
            r=a%10;
            t=t*10+r;
            a=parseInt(a/10);
        }
        
        document.write(t);
        
    }
    &lt;/script&gt;

&lt;/head&gt;

&lt;body&gt;
&lt;form&gt;
    &lt;input type=&quot;text&quot; id=&quot;str&quot;/&gt;
    &lt;input type=&quot;submit&quot; onClick=&quot;palindrome()&quot; /&gt;
&lt;form&gt;
&lt;/body&gt;
&lt;/html&gt;
</code></pre>


blocks|key|4408163|text|function+add(+num:number){++//159
let+d+:+number;+
let+a+:+number+=0;++
while(num+>+0){++++//159++15++1
++++d+=+num+%25+10;++
++++a+=+a+*+10+%2B+d;++//9++95+++951
++++num+=+Math.floor(num/10);++//+15++1++0
}
+return+a;++//951
}
console.log(add(159));|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|4408164|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>function add( num:number){  //159
let d : number; 
let a : number =0;  
while(num &gt; 0){    //159  15  1
    d = num % 10;  
    a = a * 10 + d;  //9  95   951
    num = Math.floor(num/10);  // 15  1  0
}
 return a;  //951
}
console.log(add(159));
</code></pre>


blocks|key|4408351|text|甜蜜而简单：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4408352|function+reverseNumber(num){
+++return+parseInt(num.toString().split("").reverse().join(""));
}|code-block|syntax|javascript|4408353|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>Sweet and simple:</p>
<pre><code>function reverseNumber(num){
   return parseInt(num.toString().split(&quot;&quot;).reverse().join(&quot;&quot;));
}
</code></pre>


blocks|key|4408453|text|反转一个数字，而不使用递归方法将其转换为字符串。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4408454|​|4408455|const+num+=+4578;

const+by10+=+(num)+=>+{
++return+Math.floor(num+/+10);
};
const+remBy10+=+(num)+=>+{
++return+Math.floor(num+%25+10);
};

const+reverseNum+=+(num,+str+=+"")+=>+{
++if+(num.toString().length+==+1)+return+(str+%2B=+num);
++return+reverseNum(by10(num),+(str+%2B=+remBy10(num)));
};

console.log(reverseNum(num,+""));|code-block|syntax|javascript|4408456|4408457|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>Reversing a number without converting it into the string using the recursive approach.</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>const num = 4578;

const by10 = (num) =&gt; {
  return Math.floor(num / 10);
};
const remBy10 = (num) =&gt; {
  return Math.floor(num % 10);
};

const reverseNum = (num, str = "") =&gt; {
  if (num.toString().length == 1) return (str += num);
  return reverseNum(by10(num), (str += remBy10(num)));
};

console.log(reverseNum(num, ""));</code></pre>
</div>
</div>
</p>


blocks|key|4408506|text|var+reverse+=+function(x)+{
+++if+(x+>+2147483647+%7C%7C+x+<+-2147483648+%7C%7C+x+===+0)+{
+++++++return+0;
+++}

+++let+isNegative+=+false;

+++if(x+<+0){
+++++++isNegative+=+true;
+++++++x+=+-x;
+++}

+++const+length+=+parseInt(Math.log10(x));
+++let+final+=+0;
+++let+digit+=+x;
+++let+mul+=+0;

+++for(let+i+=+length+;+i+>=+0;+i--){
+++++++digit+=+parseInt(x+/+(10**i));
+++++++mul+=+10**(length-i);
+++++++final+=+final+%2B+digit+*+mul;+
+++++++x+=+parseInt(x+%25+10**i);
+++}

+++if+(final+>+2147483647+%7C%7C+final+<+-2147483648+)+{
+++++++return+0;
+++}

+++if(isNegative){
+++++++return+-final;
+++}
+++else{
+++++++return+final;
+++}
};

+++
console.log(reverse(1534236469));
console.log(reverse(-123));
console.log(reverse(120));
console.log(reverse(0));
console.log(reverse(2,147,483,648));|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|4408507|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre class="lang-js prettyprint-override"><code>var reverse = function(x) {
   if (x &gt; 2147483647 || x &lt; -2147483648 || x === 0) {
       return 0;
   }

   let isNegative = false;

   if(x &lt; 0){
       isNegative = true;
       x = -x;
   }

   const length = parseInt(Math.log10(x));
   let final = 0;
   let digit = x;
   let mul = 0;

   for(let i = length ; i &gt;= 0; i--){
       digit = parseInt(x / (10**i));
       mul = 10**(length-i);
       final = final + digit * mul; 
       x = parseInt(x % 10**i);
   }

   if (final &gt; 2147483647 || final &lt; -2147483648 ) {
       return 0;
   }

   if(isNegative){
       return -final;
   }
   else{
       return final;
   }
};

   
console.log(reverse(1534236469));
console.log(reverse(-123));
console.log(reverse(120));
console.log(reverse(0));
console.log(reverse(2,147,483,648));
   
</code></pre>


blocks|key|4408604|text|最简单的解决方案是反转js中的任何整数。不适用于浮点数。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4408605|const+i2a+=+number.toString().split("");
const+a2i+=+parseInt(i2a.reverse().join(""));
console.log(a2i);|code-block|syntax|javascript|4408606|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>The simplest solution is to reverse any integer in js. Doesn't work with float.</p>
<pre><code>const i2a = number.toString().split(&quot;&quot;);
const a2i = parseInt(i2a.reverse().join(&quot;&quot;));
console.log(a2i);
</code></pre>


blocks|key|4408224|text|上面的代码对负数不起作用。相反，请使用以下内容：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4408225|/**
+*+@param+{number}+x
+*+@return+{boolean}
+*/
var+isPalindrome+=+function(x)+{
++++return++((x>=0)+?+((x==(x+=+parseInt(x.toString().split("").reverse().join(""))))+?+true:false)+:+false);
};|code-block|syntax|javascript|4408226|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>The above code will not work for negative numbers. Instead, use the following:</p>
<pre><code>/**
 * @param {number} x
 * @return {boolean}
 */
var isPalindrome = function(x) {
    return  ((x&gt;=0) ? ((x==(x = parseInt(x.toString().split(&quot;&quot;).reverse().join(&quot;&quot;)))) ? true:false) : false);
};
</code></pre>


<p>Below is my source code to reverse (as in a mirror) the given number.
I need to reverse the number using the reverse method of arrays.</p>
<pre><code>var a = prompt(&quot;Enter a value&quot;);
var b, sum = 0;
var z = a;
while(a &gt; 0)
{
  b = a % 10;
  sum = sum * 10 + b;
  a = parseInt(a / 10);
}
alert(sum);
</code></pre>


JavaScript: How to reverse a number?

下面是我用来反转(就像在镜像中)给定数字的源代码。我需要使用数组的反转方法来反转数字。var a = prompt("Enter a value");var b, sum = 0;var z = a;while(a > 0){  b = a % 10;  sum = sum * 10 + b;  a = parseInt(a / 10);}alert(sum);

问JavaScript:如何反转一个数字？
EN

回答 15

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问JavaScript:如何反转一个数字？EN

回答 15

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问JavaScript:如何反转一个数字？
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