String.prototype.trim()

The trim() method removes whitespace from both ends of a string. Whitespace in this context is all the whitespace characters (space, tab, no-break space, etc.) and all the line terminator characters (LF, CR, etc.).

Syntax

str.trim()

Return value

A new string representing the calling string stripped of whitespace from both ends.

Description

The trim() method returns the string stripped of whitespace from both ends. trim() does not affect the value of the string itself.

Examples

Using trim()

The following example displays the lowercase string 'foo':

var orig = '   foo  ';
console.log(orig.trim()); // 'foo'
// Another example of .trim() removing whitespace from just one side.
var orig = 'foo    ';
console.log(orig.trim()); // 'foo'

Polyfill

Running the following code before any other code will create trim() if it's not natively available.

if (!String.prototype.trim) {
  String.prototype.trim = function () {
    return this.replace(/^[\s\uFEFF\xA0]+|[\s\uFEFF\xA0]+$/g, '');
  };
}

Specifications

Browser compatibility

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

See also

• String.prototype.trimLeft()
• String.prototype.trimRight()