Difference between const and readonly in typescript

Question

Constant vs readonly in typescript

Declaring a variable as readonly will not allow us to override even if they are public properties.

How const beha

Answer 1

I think the reason for both words is probably that it's easier to implement than the alternative.

In C++, for instance, classes can have const members. But C++ has special syntax to initialize the constants before the constructor is run, so there's never really any "assignment" to the const going on, like:

class TestClass {
    const int _x;
    TestClass(int x) : _x(x) {}
}

The _x(x) initializes the _x variable before the constructor is called.

In Typescript, if they wanted to allow members to be declared const and were serious about the variables being const, they would need to add similar syntax.

"readonly" isn't really the same as const. It means, I think, something slightly different. It means "allow assignment inside the constructor, but then no more."