Function does not work when entering number javascript

Question

I have a function that reverses a string. I would like the function to return "Null" when a number is entered however when i input a number my function stops working. Is there something i am missing?

function reverseWords(words) {
    let eachLetter = words.split("");

    let reverseLetter = eachLetter.reverse();

    let combineLetter = reverseLetter.join("");

    if (typeof words !== "string") {
        return null;
    } else {
        return combineLetter;
    }
}

console.log(reverseWords(89));

The problem is that `number` variables don't have a `.split(..)` function. To fix that, you can add the `typeof words !== "string"` check at the start of the function and return `null` before calling any `string` specific functions on the attribute. — Titus, Jun 18 '22 at 11:08
Does this answer your question? [JavaScript Number Split into individual digits](https://stackoverflow.com/questions/7784620/javascript-number-split-into-individual-digits) — pilchard, Jun 18 '22 at 11:08

score 1 · Answer 1 · answered Jun 18 '22 at 11:10

1

the operations you try to perform before the if are not possible with numbers.

Put validation as the first thing your function does and everything will work.

answered Jun 18 '22 at 11:10

Emerson Moonlit

11
1

score 0 · Answer 2 · answered Jun 18 '22 at 11:13

function reverseWords(words) {

if (typeof words !== "string") {
    return null;
} else {
        
   //Split the string 
  let eachLetter = words.split("");

  let reverseLetter = eachLetter.reverse();

  let combineLetter = reverseLetter.join("");


    return combineLetter;
}

}

console.log(reverseWords('89'));

You cannot apply 'split' method on numbers. First, check for the numeric value and perform the split function only when it is a string.

Function does not work when entering number javascript

2 Answers2