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    String.prototype.trim()

    Summary

    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()

    Description

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

    Examples

    Example: 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) {
      (function() {
        // Make sure we trim BOM and NBSP
        var rtrim = /^[\s\uFEFF\xA0]+|[\s\uFEFF\xA0]+$/g;
        String.prototype.trim = function() {
          return this.replace(rtrim, '');
        };
      })();
    }
    

    Specifications

    Specification Status Comment
    ECMAScript 5.1 (ECMA-262)
    The definition of 'String.prototype.trim' in that specification.
    Standard Initial definition. Implemented in JavaScript 1.8.1.
    ECMAScript 2015 (6th Edition, ECMA-262)
    The definition of 'String.prototype.trim' in that specification.
    Standard  

    Browser compatibility

    Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
    Basic support (Yes) 3.5 (1.9.1) 9 10.5 5
    Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
    Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)

    See also

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