CODEWITHSUNDEEP
javascriptecmascript-6let
John Abraham
John Abraham

Reputation: 18781

how to use the es6 "let" keyword properly in a forloop

Maybe I'm just not understanding the es6 'let' keyword.

Question:

Wy would iterate(10) only iterate 4 times? Why is the final output 15?

function iterate(count){
  for(let i = 0; i < count; i++){
    i += i
    console.log('inside', i);
  }
  console.log('outside', i);
}
iterate(10);
//0
//inside 2
//inside 6
//inside 14
//outside 15

How should I go about using let in a for loop? When should I think to use let.

Upvotes: 1

Views: 100

Answers (1)

dfsq
dfsq

Reputation: 193261

why would iterate(10) only iterate 4 times?

Because you increment i by itself, basically multiply by two in each iteration:

i += i

It has nothing to do with let. The same result would be with var.

why final output be 15?

That should actually throw a Reference error because i is not available outside of the loop.

Upvotes: 3

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