js . Find the first palindrome string in the array

Here's an array of strings words , Find and return... In the array First palindrome string . If there is no string that meets the requirements , Return to one An empty string “” .

Palindrome string For the definition of ： If a string is read in the same way as it is read in the opposite direction , Then the string is a Palindrome string .

Example 1：

Input ：words = [“abc”,“car”,“ada”,“racecar”,“cool”]
Output ：“ada”
explain ： The first palindrome string is “ada” .
Be careful ,“racecar” It's also a palindrome string , But it's not the first .
Example 2：

Input ：words = [“notapalindrome”,“racecar”]
Output ：“racecar”
explain ： The first and only palindrome string is “racecar” .

source ： Power button （LeetCode）

/** * @param {string[]} words * @return {string} */
var firstPalindrome = function(words) {
    
    for(let i =0;i<words.length;i++){
    
        let str = words[i]
        let len = str.length
        // Intermediate index 
        let index = parseInt(len / 2)
       //  The left character 
        let str1 = str.substring(0,index)
        // On the right side 
        let str2=str.substring(len-index,len)
        if(str2.split("").reverse().join("")==str1){
    
            return str
        }
    }
    return ""
};