JavaScript - convert string to integer

In this article, we can find different ways how to parse integer numbers with parseInt function in JavaScript.

Integer parsing example

This section shows how to convert with built-in parseInt method some text to an integer.

// ONLINE-RUNNER:browser;

var text = '123';
var number = parseInt(text);

console.log(number === 123); // true

Using the parseInt() method we can also parse floating point number and it will be rounded to an integer, look at the below example.

// ONLINE-RUNNER:browser;

var text = '123.12';
var number = parseInt(text);

console.log(text);
console.log(number);
console.log(number === 123); // true

Parsing numbers with unit examples

parseInt method during conversion ignores all characters that are not digits and occur after the number. It makes it possible to parse numbers with units.

// ONLINE-RUNNER:browser;

var number = parseInt('1px'); // pixels (px)
console.log(number === 1); // true

var number = parseInt('2cm'); // centimeters (cm)
console.log(number === 2); // true

var number = parseInt('3in'); // inches (in)
console.log(number === 3); // true

var number = parseInt('4%'); // percentages (%)
console.log(number === 4); // true

See also

1. JavaScript - how to convert string to number?