CODEWITHSUNDEEP
javascript
George
George

Reputation: 2594

Why can't I declare a let variable with the same name as function body in Chrome

Chrome 67 (the latest version as of this writing) lets me do this

function foo(x, y) {
    var x = 5;
    console.log(x, y);
}
foo(1,2);
// prints 5 2

but not this

function foo(x, y) {
    let x = 5;
    console.log(x, y);
}
foo(1,2);
// Throws a SyntaxError: Identifier 'x' has already been declared

Is this behavior standard-defined?

Upvotes: 0

Views: 134

Answers (1)

keul
keul

Reputation: 7819

Using the old var keyword you were free to declare a variable multiple times without issues (well... this was an issue by itself).

The const and let keywords have a better behavior. In your case: you don't need to re-declare x as it's already declared as an argument of the foo function, so you can assign something to it directly (overriding parameters is not something very clean, but is legit).

Upvotes: 2

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