Javascript 空 function 和原型使用

Question

MathUtils = function() {};

MathUtils.prototype.sum = function(number1, number2) {
        return number1 + number2;
}

MathUtils.prototype.substract = function(number1, number2) {
    return number1 - number2;
}

The above is a code snippet that I am currently testing using Jasmine. Can someone please help me understand what is the significance of Line no 1? The file name is MathUtils.js. Also it would be really helpful if I could get a brief on what.prototype is.

Answer 1

The significance of line 1 is that it creates an Object instance. Prototype is the chain that mimics inheritance in JavaScript.