Reverse a String using for loop

JavaScript
1

Tell us what’s happening:
I am swapping two characters in for loop but why is it not going as expected, not able to figure out why this solution is not working. Kindly help

Your code so far


function reverseString(str) {
  let n = str.length;
  let temp = '';
  for(let i=0;i<n/2;i++) {
    
    temp = str[i];
    str[i] = str[n-1-i];
    str[n-1-i] = temp;
  }
  return str;
}

reverseString("string");

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Link to the challenge:
https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/basic-algorithm-scripting/reverse-a-string

2

Strings are immutable. You cannot swap their characters but you can concatenate strings to other strings to form new strings.

1 Like
3

Thank you @hbar1st :slightly_smiling_face:

4

What you can do though is use the spread/rest operator ‘...’ to put that string into an array and then you can start swapping characters around.

let strArray = [...str]
1 Like
5

Yes, I totally forgot about the spread operator :sweat_smile: Thanks for the valuable response @camelcamper

6

Here’s what I got using a for loop. Keep in mind it’s pretty impractical given the alternative is one line of code:
function reverseString(str) {
let switchArr = […str];
let tempArr = [];
for(let i = 0; i < str.length; i++){
let j = switchArr[i];
tempArr.unshift(j);
}
let finalStr = tempArr.join(’’);
return finalStr;
}

reverseString(“hello”);

1 Like