jquery.trim compared to string.trim

Question

Is there any difference between jQuery trim and native JavaScript one? Is there any other behaviour, safety, performance?

Accepted Answer

JavaScript `.trim()` was defined in ES 5.1, and will not work for IE<9. Therefore, if you already use jQuery you could use the less performant `$.trim()`

jQuery's `$.trim()` Method does:

```
trim: function( text ) {
    return text == null ? "" : ( text + "" ).replace( rtrim, "" );
}
```

where `rtrim` is basically this RegExp

```
new RegExp( "^" + whitespace + "+|((?:^|[^\\])(?:\\.)*)" + whitespace + "+$", "g" )
```

and `whitespace` is represented as this Group:

```
"[\x20\t\r\n\f]"
```

In JavaScript (ES6) it's defined as:

21.1.3.25 String.prototype.trim ( )

This function interprets a String value as a sequence of UTF-16 encoded code points, as described in 6.1.4.

The following steps are taken: Let O be RequireObjectCoercible(this value). Let S be ToString(O). ReturnIfAbrupt(S). Let T be a String value that is a copy of S with both leading and trailing white space removed. The definition of white space is the union of WhiteSpace and LineTerminator. When determining whether a Unicode code point is in Unicode general category “Zs”, code unit sequences are interpreted as UTF-16 encoded code point sequences as specified in 6.1.4. Return T. NOTE The trim function is intentionally generic; it does not require that its this value be a String object. Therefore, it can be transferred to other kinds of objects for use as a method.

So let alone the implementation of JS's `.trim()` to browser vendors, the point is quite clear: Remove any representation of newlines or spaces from the beginning and end of a String.

jquery.trim compared to string.trim

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