Javascript String format(opts)

String.prototype.format = function(opts) {
    var option,//from   ww w .j  a  v  a 2 s.c  o m
        regex,
        formatted = this;

    for (option in opts) {
        regex = new RegExp('#{' + option + '}', 'g');
        formatted = formatted.replace(regex, opts[option]);
    }

    return formatted;
};


console.log('Hello, there! Are you #{name}?'.format({name: 'John'}));
console.log('My name is #{name} and I am #{age}-years-old'.format({name: 'John', age: 13}));