js替换字符串

js替换最后一次出现的匹配的字符串

var v = "abbbabbbbab";
        var pos = v.lastIndexOf("a");
        var vv = v.substring(0, pos) + "c" + v.substring(pos+1, v.length);
        alert(vv);

js直接替换第一次出现的匹配字符串

var str = "adksdjfldjfoeoxl";
var t = str.lastIndexOf("d");
str = str.replace(/d/, "c");
alert(str);