Basic Algorithm Scripting: Mutations, code always returning false

Tell us what’s happening:
Can someone explain why the output of the code is always false? Its supposed to return true whenever all of the characters in the second word are present in the first word, regardless of case. I converted both strings into an array of individual uppercase letters and tried to use .indexOf to check if the character is present or not.

Your code so far

function mutation(arr) {
arr[0] =  arr[0].toUpperCase();
arr[1] = arr[1].toUpperCase();
arr[0] = arr[0].split('')
arr[1] = arr[1].split('')

for(let i = 0; i< arr[1].length;i++ ){
if(arr[0].indexOf(arr[1][i] == -1)){
return false
} else return true


mutation(["hello", "Hello"]);

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Challenge: Mutations

Link to the challenge:

Take a closer look at what exactly you are passing to the indexOf() method.

Notice also that currently you are returning in both cases (whether character is in arr or not), this means that your function always will check just a single character.