1、替换全部

String.prototype.replaceAll = function(s1, s2) {
    return this.replace(new RegExp(s1, "gm"), s2)
}

2、清除空格

String.prototype.trim = function() {
    var reExtraSpace = /^\s*(.*?)\s+$/;
    return this.replace(reExtraSpace, "$1")
}