Why does my isogram checker return true too early?

[shivajikobardan]

TL;DR

codewars kata not passing all tests.

https://www.codewars.com/kata/54ba84be607a92aa900000f1/train/javascript
This is my code for it.

function isIsogram(str) {
  let i, j;
  let str1 = str.toLowerCase();
  for (i = 0; i < str1.length; i++) {
    for (j = i + 1; j < str1.length; j++) {
      if (str1[i] === str1[j]) {
        return false;
      }
      else {
        return true;
      }
    }
  }
}
isIsogram("Dermatoglyphics");

My code isn't passing all tests, why? I feel this works fine.

 

[Halc]

Well for one, the code seems to return unconditionally on the first pass of either loop.

 

[pbuk]

Think about how many times you have check letters before you can return true.

 

[pbuk]

My code isn't passing all tests, why? I feel this works fine.

Which test is it not passing? Note I already know this, I am asking because YOU need to know; I don't need any help.

When you have identified it, step through the code in your head/on paper/in debug until you get to the point where it fails, or just log everything to the console and look for it.

 

[shivajikobardan]

just log everything to the console and look for it.

there's no error in console.

 

[shivajikobardan]

got it.

 

[pbuk]

there's no error in console.

I meant that you should log the progress of your loop to the console. This is how you debug code.

 

[pbuk]

Readers may be interested to know that JavaScript now has a Set object.