CODEWITHSUNDEEP
javascriptnode.jsecmascript-6
codyc4321
codyc4321

Reputation: 9682

Freezing const variables completely

Looking at the below code, I found a strange and seemingly bad problem with const:

const path = require('path');


function reWritePath() {

    let path = 'blah';

    console.log(path);
}


reWritePath();

This seems to go against the point of const, and I'm surprised to find it can be rewritten in subscopes. Is there a clean way to completely freeze a variable so this can't happen anywhere across the file?

Upvotes: 0

Views: 74

Answers (2)

David Knipe
David Knipe

Reputation: 3454

AKX is right - there are really two separate variables named path. They just happen to have the same name.

Consider this:

const x = 0;

function reWritePath() {
    let x = 1;
    console.log(x);
}

reWritePath();
console.log(x);

The output of this will be:

1
0

If that's confusing, try renaming one of the variables:

const x = 0;

function reWritePath() {
    let y = 1;
    console.log(y);
}

reWritePath();
console.log(x);

Upvotes: 0

AKX
AKX

Reputation: 169051

Those are not the same variables. The same names, yes, but in different scopes.

There is no way of strictly not allowing this to happen -- instead, you should use a linter that can look for name shadowing so you'll at least notice this happening.

Upvotes: 4

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