How to make a input in HTML in JS to integer

Question

So I can not make the input into a integer. I want to turn this into a int so then it can calculate the age of you. I have been researching but can not find the right answer. HTML CODE:

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>learn</title>
<script src="script.js"></script>
</head>
<form action="/learn.html">
    <b>Year Born:</b> <input id="input988744" type="value">
</form>
<button onClick="calculateAge(birthYear);">Summit</button>
<body>
</body>
</html>

Javascript Code:

/*
Function
*/

// var
var birthYear;
birthYear = document.getElementById("input988744");

// function
function calculateAge(birthYearInFun) {
    "use strict";
    console.log(2018 - birthYearInFun); // make it a number
}

On what line? @Mirodinho

George Davis
– George Davis

2018-10-28 01:10:52 +00:00
Commented Oct 28, 2018 at 1:10 — George Davis
– George Davis, Commented Oct 28, 2018 at 1:10

NAVIN · Accepted Answer · 2018-10-28 01:41:18Z

4

2 things needs to be changed

HTML:Change type of <input> from text to number, number can be negative so can add parameter min="1900" to stop from entering date earlier then 1900
```
<b>Year Born:</b> <input id="input988744" type="number" min="1900">
```
Javascript: Need to fetch value of HTML element, thus add .value adter getElementById, as getElementById gives HTML element not its value. To be on safer side use parseInt() or Number() over birthYear
```
var birthYear;
birthYear = Number(document.getElementById("input988744").value);
or
birthYear = parseInt(document.getElementById("input988744").value);
```

Both these will make birthYear number.

edited Oct 28, 2018 at 1:41

answered Oct 28, 2018 at 1:30

NAVIN

3,3174 gold badges21 silver badges32 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

SakoBu · Accepted Answer · 2018-10-28 01:10:55Z

What you really want it looks like is the input type to be a date... Check out the snippet below

legend {
    background-color: #000;
    color: #fff;
    padding: 3px 6px;
}

.output {
    font: 1rem 'Fira Sans', sans-serif;
}

input {
    margin: .4rem;
}

label {
    display: inline-block;
    text-align: right;
    width: 20%;
}

<fieldset>
    <legend>Choose trip dates</legend>

    <div>
        <label for="start">Start</label>
        <input type="date" id="start" name="trip"
               value="2018-07-22"
               min="2018-01-01" max="2018-12-31" />
    </div>

    <div>
        <label for="end">End</label>
        <input type="date" id="end" name="trip"
               value="2018-07-29"
               min="2018-01-01" max="2018-12-31"/ >
    </div>

</fieldset>

ASG · Accepted Answer · 2018-10-28 01:11:09Z

1

You can access the value of the input field as birthYearInFun.value as Mirodinho said and then if it a string, convert it to a number using parseInt().

birthYear = parseInt(document.getElementById("input988744").value)

answered Oct 28, 2018 at 1:11

ASG

2134 silver badges10 bronze badges

Collectives™ on Stack Overflow

How to make a input in HTML in JS to integer

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related