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JavaScript

Posted by Jackson Monk
Jackson Monk
4,527 Points

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?

<html>
<head></head>
<body>
<script>

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 ++) {

        parseInt(numarr[z]);

        if (isNaN(numarr[z])) {

            valid = false;
            break;
        }

}

    if (valid === true) {
        sum();
    }

    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');
                  li.appendChild(text);
                  ul.appendChild(li);

        text = undefined;
        li = undefined;
                }
            }
        }
    }
}
}
program();
});

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';
});
};

</script>
</body>
</html>
Steven Parker
Steven Parker
229,732 Points
Steven Parker
Steven Parker
229,732 Points

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

2 Answers

Steven Parker
Steven Parker
229,732 Points
Steven Parker
Steven Parker
229,732 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.

Jackson Monk
Jackson Monk
4,527 Points
Jackson Monk
Jackson Monk
4,527 Points

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
229,732 Points
Steven Parker
Steven Parker
229,732 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.