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What am I doing wrong to convert this?

For this project I need to convert every string value in the numarr array to a number, but my parseInt method isn't working. Can anyone see what my problem is?


window.onload = function() {

let body = document.getElementsByTagName('body')[0];
let input = document.getElementsByTagName('input')[0];
let button = document.getElementsByTagName('button')[0];
let ul = document.getElementsByTagName('ul')[0];

button.addEventListener('click', () => {

    let numarr;
    let numbers;
    let counter = 0;
    let valid = true;
    let funct;
    let text;
    let li;

    function program() {

    numbers = input.value;
    numarr = numbers.split(' ');

    for (let z = 0; z < numarr.length; z ++) {


        if (isNaN(numarr[z])) {

            valid = false;


    if (valid === true) {

    else {
        alert("Input must be a number. Please try again");

   function sum() {

    for (let a = 0; a < numarr.length; a ++) {

        for (let b = a + 1; b < numarr.length; b ++) {

            for (let c = b + 1; c < numarr.length; c ++) {

                if (numarr[a] + numarr[b] + numarr[c] === 0) {

                  text = document.createTextNode(numarr[a] + ", " + numarr[b] + ", " + numarr[c]);
                  li = document.createElement('li');

        text = undefined;
        li = undefined;

body.style.backgroundColor = 'violet';
body.style.color = 'yellow';

input.addEventListener('mouseover', () => {
    input.style.backgroundColor = 'lightgray';

input.addEventListener('mouseout', () => {
    input.style.backgroundColor = 'white';

button.style.backgroundColor = 'tomato';
button.style.color = 'orange';
button.style.border = 'tomato';

button.addEventListener('mouseover', () => {
    button.style.backgroundColor = 'orange';
    button.style.color = 'tomato';

button.addEventListener('mouseout', () => {
    button.style.backgroundColor = 'tomato';
    button.style.color = 'orange';

Steven Parker
Steven Parker
229,967 Points

Use the instructions for code formatting in the Markdown Cheatsheet pop-up below the "Add an Answer" area. :arrow_heading_down: ย  Or watch this video on code formatting.

2 Answers

Steven Parker
Steven Parker
229,967 Points

This code is referring to elements with tags like "input", "button" and "ul"; but there's nothing in the body except for the script itself.

Also, "parseInt" doesn't change its argument, it returns a number result. To make use of that result you would need to assign it to a variable or pass it as an argument to a function.

So you're saying to get the number I'm looking for, I have to assign the parsed values to a variable or pass them to a function? (Just want to be clear)

Steven Parker
Steven Parker
229,967 Points

For example, if you wanted to change the the value in the variable from a string to a number:

        numarr[z] = parseInt(numarr[z]);

Calling "parseInt" by itself performs the conversion but does not change anything.