I'm trying to solve 557 on leetCode with two pointers, and I found a strange behavior, which I cannot explain.
Below is my code
/**
* @param {string} s
* @return {string}
*/
var reverseWords = function(s) {
// return s.split(" ").map(w => w.split("").reverse().join("")).join(" ")
let arr = s.split(" "), w
for(let i = 0; i < arr.length; i++){
let x = arr[i], left = 0, right = x.length - 1, holder = null
while(left < right){
holder = x[left]
x[left] = x[right]
x[right] = holder
left += 1
right -= 1
}
}
return arr.join(" ")
};
and example "Let's take LeetCode contest"
while I can move the while loop to a function and solve it in a different way, I'm not sure why x is not changing, from my understanding this is an array item and can be changed.
This happens because the variable "x" is not an array but a String which comes from the variable "arr" to make it work you need to change
let x = arr[i]
to
let x = arr[i].split("")
the correct code is:
var reverseWords = function(s) {
// return s.split(" ").map(w => w.split("").reverse().join("")).join(" ")
let arr = s.split(" "), w
for(let i = 0; i < arr.length; i++){
let x = arr[i].split(""), left = 0, right = x.length - 1, holder = null
while(left < right){
holder = x[right]
x[right] = x[left]
x[left] = holder
left += 1
right -= 1
}
arr[i] = x.join("");
}
return arr.join(" ")
};