9\. Palindrome Number
# 9. Palindrome Number (opens new window)
# Description
Difficulty: Easy
Related Topics: Math (opens new window)
Given an integer x, return true if x is palindrome integer.
An integer is a palindrome when it reads the same backward as forward.
- For example,
121is a palindrome while123is not.
Example 1:
Input: x = 121
Output: true
Explanation: 121 reads as 121 from left to right and from right to left.
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Example 2:
Input: x = -121
Output: false
Explanation: From left to right, it reads -121\. From right to left, it becomes 121-. Therefore it is not a palindrome.
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Example 3:
Input: x = 10
Output: false
Explanation: Reads 01 from right to left. Therefore it is not a palindrome.
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Constraints:
- -231 <= x <= 231 - 1
Follow up: Could you solve it without converting the integer to a string?
# Solution
Language: JavaScript
/**
* @param {number} x
* @return {boolean}
* 回文数是指正序和倒序读都是一样的整数
* 1.数字转换为字符串
*/
var isPalindrome = function(x) {
return +x.toString().split('').reverse().join('') === x;
};
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