Answers for "looping in js array"

js loop array

var colors = ["red","blue","green"];
for (var i = 0; i < colors.length; i++) {
    console.log(colors[i]);
}

loop array

String.prototype.replaceAt = function (index, char) {
    return this.substr(0, index) + char + this.substr(index + char.length);
}
mystring.replaceAt(4, '')