Difference between freeze and seal

Question

I just heard about the JavaScript methods freeze and seal, which can be used to make any Object immutable.

Here\'s a short example how to u

Answer 1

You can now force a single object property to be frozen instead of freezing the whole object. You can achieve this with Object.defineProperty with writable: false as a parameter.

var obj = {
    "first": 1,
    "second": 2,
    "third": 3
};
Object.defineProperty(obj, "first", {
    writable: false,
    value: 99
});

In this example, obj.first now has its value locked to 99.