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('') //转化为数组 let res = Number(arr.reverse().join('')) if(x===res){ return true }else if(arr[0]===0){ return false }else if(str!==res){ return false } } };

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