JavaScript const Keyword

Question

Does the

const

keyword in JavaScript create an immutable reference to immutable data structures? [I'm assuming that immutable data structures exist in JavaScript.]

For

string

it appears to do so:

var x = "asdf";

const constantX = x;



alert("before mutation: " + constantX);

x = "mutated"

alert("after mutation: " + constantX);

output:

before mutation: asdf

after mutation: asdf

http://jsfiddle.net/hVJ2a/

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Answer 1

Yes, it does, but it is not been standardized and is not supported in all browsers.

See this MDN article on the const keyword for details and compatability.

JavaScript const Keyword

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