Javascript常用方法函数收集

function cutstr(str, len) {
var temp,
    icount = 0,
    patrn = /[^\x00-\xff]/，
    strre = "";
for (var i = 0; i < str.length; i++) {
    if (icount < len - 1) {
        temp = str.substr(i, 1);
            if (patrn.exec(temp) == null) {
               icount = icount + 1
        } else {
            icount = icount + 2
        }
        strre += temp
        } else {
        break;
    }
}
return strre + "..."
}

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

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

function ltrim(s){ return s.replace( /^(