How to get number value from input in JavaScript

Published: · Reading time: 2 min

Working with HTML inputs may require handling proper value types, like numbers. However, the value property of an input element will return a string-type value by default.

Default value

Given the input with a type of number let’s get its value.

<input type="number" value="42">

By default, the value property of the input element will always return a string type, even if the input type is a number.

const numberInput = document.querySelector("input[type=number]")

numberInput.value // "42"

💡 NOTE: the type attribute of the input element can be equal to a many different values, but its value property will always return a string-type value

Number value

To get the number type value from the input element you can use one of two approaches.

The first one is to convert the string value to a number value with either the parseInt or parseFloat method (depending on your needs).

const numberInput = document.querySelector("input[type=number]")

parseInt(numberInput.value) // 42

This approach is useful when working with input types like text or search, as the user may input a numeric value, and you may want to capture that.

If the input value is not a number the parseInt or parseFloat will return a NaN value.

parseInt and parseFloat methods works in all browsers.

The second approach is to use the valueAsNumber property instead of the value property on an input element.

const numberInput = document.querySelector("input[type=number]")

numberInput.valueAsNumber // 42

The valueAsNumber property will always work on input types like: number, range, date, month, time, and week. But if you use this property say on a text type input it will return a NaN value.

This is a more straightforward approach especially if you know the input type you’re working with. valueAsNumber property is supported in all browsers as well.

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