String.prototype.replace()
The replace() method returns a new string with some or all matches of a pattern replaced by a replacement.
The pattern can be a string or a , and the replacement can be a string or a function to be called for each match.
语法：
str.replace(regexp|substr, newSubStr|function[, flags])
Parameters
regexp (pattern) A object or literal. The match is replaced by the return value of parameter #2. substr (pattern) A that is to be replaced by newSubStr. It is treated as a verbatim string and is notinterpreted as a regular expression. newSubStr (replacement) The that replaces the substring received from parameter #1. A number of special replacement patterns are supported; see the "" section below. function (replacement) A function to be invoked to create the new substring (to put in place of the substring received from parameter #1). The arguments supplied to this function are described in the "" section below. 例子： 例1：
var str = \'Twas the night before Xmas...\'; var newstr = str.replace(/xmas/i, \'Christmas\'); console.log(newstr); // Twas the night before Christmas...