reversePrefixOfWord.js

/**
 * @param {string} word
 * @param {character} ch
 * @return {string}
 */
var reversePrefix = function (word, ch) {
    let findIndexHere = word.indexOf(ch)
    let sliceAndReverse = word.slice(0, findIndexHere + 1).split('').reverse()
    let sliceSecond = word.slice(findIndexHere + 1).split('')
    return sliceAndReverse.concat(sliceSecond).join('')
};




/*
Example 1:
Input: word = "abcdefd", ch = "d"
Output: "dcbaefd"
Explanation: The first occurrence of "d" is at index 3. 
Reverse the part of word from 0 to 3 (inclusive), the resulting string is "dcbaefd".

Example 2:
Input: word = "xyxzxe", ch = "z"
Output: "zxyxxe"
Explanation: The first and only occurrence of "z" is at index 3.
Reverse the part of word from 0 to 3 (inclusive), the resulting string is "zxyxxe".

Example 3:
Input: word = "abcd", ch = "z"
Output: "abcd"
Explanation: "z" does not exist in word.
You should not do any reverse operation, the resulting string is "abcd".
 */