supplant.js

// Wanted to check out the example from Frontend Masters by David Crockford

var template = '<table border="{border}">' +            // 
    '<tr><th>Last</th><td>{last}</td></tr>' +           // Hold table format in var template
    '<tr><th>First</th><td>{first}</td></tr>' +         // 
    '</table>';                                         // 

var data = {                                            // values to be replaced with RegEx
    first: "Carl",                                      // 
    last: "Jose",                                       //
    border: "3"                                         // must be string
};                                                      //


if (typeof String.prototype.supplant !== 'function') {  // if there's no supplan prototype in String object 
    String.prototype.supplant = function (o) {          // define it
        return this.replace(/{([^{}]*)}/g,              // regex pattern to match to match "{abc}"
        function (a, b) {                               // accept two params 
            var r = o[b];                               // new var hold the index of object passed and matched
            return typeof r === 'string' ? r : a;       // return if r is string else return whatever value
        });
    };
}
mydiv.innerHTML = template.supplant(data);              // write to div