[removed] How to avoid addition of a new property in a function?

Question

I am a JS newbie, reading a book Javascript Patterns for understanding. One of the code snippets I could see :

var myFunc = function param() {
...
...
};
myFu         


        

Answer 1

JavaScript never really had any options to secure your objects but starting in ECMAScript 5 you can now freeze an object.

var o = { a: 1, b: 2 };
Object.freeze(o);
console.log(o.a); // 1
o.a = 2;
console.log(o.a); // 1

There is also a new context known as strict mode where an error can be thrown.

function processObject(o) {
    "use strict";
    delete o.a; // throws a TypeError
}