CODEWITHSUNDEEP
javascriptwhile-loop
Коля Устименко
Коля Устименко

Reputation: 19

What's wrong with my reverse() function while?

My code

When i use word cat the function doesn't return anything.

function reverse(str) {
  let result = '';
  let i = str.length-1;
  while ( i < 0) {
    result = result + str[i];
    i--;
  }
  return result;
}// END```

Upvotes: 0

Views: 42

Answers (4)

Adrian Brand
Adrian Brand

Reputation: 21638

You could use reduce

const reverse = str => str.split('').reduce((result, char) => char + result);

console.log(reverse('cat'));

Upvotes: 0

kunl
kunl

Reputation: 1195

You had a typo and a logic error:

function reverse(str) {
  let result = '';
  let i = str.length - 1;  // str.length
  while (i >= 0) { // greater than equal to :)
    result = result + str[i];
    i--;
  }
  return result;
}

Upvotes: 0

ellipsis
ellipsis

Reputation: 12152

Use str.length; instead of str.legth-1; legth is not a function. The function in length

function reverse(str) {
  let result = '';
  let i = str.length;
  while (i--) {
    result = result + str[i];
  }
  return result;
}
console.log(reverse('ellipsis'))

Upvotes: 0

Nina Scholz
Nina Scholz

Reputation: 386570

You need to take length and the check for greater or equal than zero for the loop.

function reverse(str) {
    let result = '';
    let i = str.length - 1;
    while (i >= 0) {
        result = result + str[i];
        i--;
    }
    return result;
}

console.log(reverse('cat'));

A slightly shorter approach with decrementing and check in one.

function reverse(str) {
    let result = '',
        i = str.length;

    while (i--) result = result + str[i];
    return result;
}

console.log(reverse('cat'));

Upvotes: 1

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