jquery.trim与string.trim相比 [英] jquery.trim compared to string.trim

问题描述

jQuery trim和本机JavaScript one之间有什么区别吗?

Is there any difference between jQuery trim and native JavaScript one?

还有其他行为，安全性和性能吗?

Is there any other behaviour, safety, performance?

推荐答案

JavaScript .trim()在ES 5.1中定义，并且不适用于IE< 9 .因此，如果您已经使用jQuery，则可以使用性能较低的$.trim()

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的 $.trim()方法可以:

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

其中rtrim基本上是此RegExp

where rtrim is basically this RegExp

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

和whitespace表示为该组:

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

---

在 JavaScript (ES6)中定义为:

---

In JavaScript (ES6) it's defined as:

21.1.3.25 String.prototype.trim()

21.1.3.25 String.prototype.trim ( )

此函数将字符串值解释为UTF-16编码的代码点的序列，如6.1.4中所述.

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

采取以下步骤: 令O为RequireObjectCoercible(此值). 令S为ToString(O). ReturnIfAbrupt(S). 令T为一个String值，它是S的副本，其中前导空格和尾随空格均已删除.空白的定义是WhiteSpace和LineTerminator的结合.确定Unicode代码点是否在Unicode通用类别"Zs"中时，代码单元序列将解释为6.1.4中指定的UTF-16编码的代码点序列. 返回T. 注:修整功能是有意通用的.它不需要其this值是String对象.因此，可以将其转移到其他类型的对象中用作方法.

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.

因此，更不用说对浏览器供应商实施JS的.trim()了，这一点很明确:
从字符串的开头和结尾删除换行符或空格的任何表示形式.

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.

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