Tell us what’s happening:
I’m confused with var loop scope. I think my confusion might have to do with understanding of for loops as well. The code below is from w3schools and is meant to be a simple explanation of var loop scope.
I don’t understand why i can ever be 10. Can someone explain it to me?
var i = 5;
for (var i = 0; i < 10; i++) {
// some statements
}
// Here i is 10
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Challenge: Compare Scopes of the var and let Keywords
var creates variables that are function scoped, so both are in the same scope, so first you have var i = 5 and then i becomes 0 with var i = 0
in the loop you have that at each iteration i < 10 is checked - at the end i becomes 10 with one last i++, but i < 10 is false so the loop stops, but i is 10 now
Thank you for the reply.
What I still don’t understand is since we have the condition that i must be less than 10, why is the last i++ allowed, which makes i=10?
the loop doesn’t know that i will be 10, so what happens is that i++ execute, then i < 10 is checked, if it’s true the loop body is run, otherwise the loop stops
It’s the sequence of events that I didn’t understand but it makes sense now. The condition is evaluated and if true, the statement block will run. Then the incrementing happens which in this case makes i=10, but when loop runs again, the condition i < 10 is not satisfied and loop stops.
Thank you @G00njan and @ilenia
