How can I do string interpolation in JavaScript?

Question

Consider this code:

var age = 3;

console.log(\"I\'m \" + age + \" years old!\");

Are there any other ways to insert the value of a variabl

Answer 1

Supplant more for ES6 version of @Chris Nielsen's post.

String.prototype.supplant = function (o) {
  return this.replace(/\${([^\${}]*)}/g,
    (a, b) => {
      var r = o[b];
      return typeof r === 'string' || typeof r === 'number' ? r : a;
    }
  );
};

string = "How now ${color} cow? {${greeting}}, ${greeting}, moo says the ${color} cow.";

string.supplant({color: "brown", greeting: "moo"});
=> "How now brown cow? {moo}, moo, moo says the brown cow."