JavaScript Challenge - Unique Characters in a String

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Hey Everyone –

I am working through the unique characters challenge and am stuck at 3/5 tests passed. I am not sure what the five tests are, so having trouble figuring out what I am missing. Mind taking a look at my code below? Thank you!!

function uniqueCharacters(stringIn) {
for(var i=0; i < stringIn.length; i++){
for(var j=0; j < stringIn.length; j++){
if(stringIn[i] === stringIn[j]){
return false
}else{
return true
}
}
}
}

// Leave this so we can test your code:

module.exports = uniqueCharacters;

In my view the issues could be:

  • The i and j have to be different. i.e. the nested (2nd) loop should start like j=i+1
  • by putting “return true” at the end, even if the loops find a double letter in the middle of the string, it will show True if the last i and j are different. Better to put a boolean variable = true before the loops and change it to false only if you find stringIn[i] = stringIn[j]

function uniqueCharacters(stringIn) {
let b=true;
for(var i=0; i < stringIn.length; i++){
for(var j=i+1; j < stringIn.length; j++){
if(stringIn[i] === stringIn[j]){
return false
}
}
}
return b
}

1 Like
function uniqueCharacters(stringIn) { // change all letters to lower cases since e.g. A is not equal to a // sort the string to avoid nested loops and reduce time complexity // change the string to array to be able to use array methods const stringToArray = stringIn.toLowerCase().split("").sort(); let result = true; for (let i=0; i < stringToArray.length-1; i++) { if (stringToArray[i]===stringToArray[i+1]) { result = false; } } if (stringIn===""){ console.log('Your string is empty') } else { return result; } }; console.log(uniqueCharacters('apple'));