What are palindromes in JavaScript? How to judge?

In JS, a palindrome number refers to an integer that reads the same in forward order (from left to right) and reverse order (from right to left). How to find a palindrome number: first convert the number into an array ; Then use reserve() to reverse the order of the elements in the array; then convert the reversed array into a number; finally use the "===" operator for equality comparison, and if equal, it is a palindrome number.

The operating environment of this tutorial: windows7 system, javascript version 1.8.5, Dell G3 computer.

Determine whether an integer is a palindrome number. A palindrome number is an integer that reads the same in forward order (from left to right) and reverse order (from right to left).

Example 1:

输入: 121
输出: true

Example 2:

输入: -121
输出: false

Explanation: Reading from left to right, it is -121. Reading from right to left, it is 121- .

So it is not a palindrome number.

Example 3:

输入: 10
输出: false

Explanation: Read from right to left, it is 01.

So it is not a palindrome number.

Problem-solving ideas

The solution I use is string flipping. First convert the test number into a string, because the array has a reserve() method, so Need to convert the string into an array before flipping it

/**
 * @param {number} x
 * @return {boolean}
 */
var isPalindrome = function(x) {
    // 负数不是一个回文数
    if(x<0){
        return false
    }
    // 对大于0的数进行判断
    else if(x>=0){
        let str = x.toString()  //转化为字符串
        let arr = str.split(&#39;&#39;) //转化为数组
        let res = Number(arr.reverse().join(&#39;&#39;))
        if(x===res){
            return true
        }else if(arr[0]===0){
            return false
        }else if(str!==res){
            return false
        }
    }
};

[Related recommendations: javascript learning tutorial]

The above is the detailed content of What are palindromes in JavaScript? How to judge?. For more information, please follow other related articles on the PHP Chinese website!