Need help with Caesar's Cipher project

JavaScript
1

I tried a really different approach, and it almost works, but I can’t work out why only half of the cipher translates; I can’t see why the rotation issue would apply here.
ie. console.log(arr); // FEEE CBDE CAMC

:confused:

function rot13(str) {

 var arr = str.split("");
const alphaKey = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".split("");
const rot13Key = "NOPQRSTUVWXYZABCDEFGHIJKLM".split("");
  
for (let i = 0; i < arr.length; i++) {
    for (let j = 0; j < rot13Key.length; j++) {
      if (arr[i] === alphaKey[j]) {
        arr[i] = rot13Key[j];
      }
    }
  }
console.log(arr.join(""));
}

rot13("SERR PBQR PNZC");
2

Hi @hjm!

Welcome to the forum!

I moved your question out of the year old post and into a new topic because you will get more responses this way.

3

thank you so much! I really appreciate the help! My first time posting…

1 Like
4

let’s say that arr[i] is equal to A
so it is changed to N
the j loop continues and at one point arr[i] === alphaKey[j] is true again

can you see the issue?
that is also the reason of why exactly half the letters are not changed

2 Likes
5

Ah! is it that when later on, arr[i] is === N, because of the previous substitution, it can’t change back to A?

Thanks you so much, by the way. It’s been doing my nut in…

6

the issue is that it is changed back to A

1 Like
7

Thanks - I think I get it. I really appreciate you taking the time to help!

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8

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