JavaScript - how to convert string to integer number?

In this post we can find different ways of how to parse integer number with parseInt function in JavaScript.

Integer parsing example

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

// ONLINE-RUNNER:browser;

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

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

Using parseInt() method we can also parse floating point number and it will be rounded to integer, look at 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 number with unit examples

parseInt method during conversion ignores all characters that are not digits and occur after number. It makes 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?