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JavaScript Using let with for Loops

About the different values of 'i'

I get that the function in the event handler gets evaluated at the moment the user clicks the button, not when the for loop runs, and that's why the i variable, when declared with var, equals 10.

When using let each event handler gets a refence to its very own i, each with a different value. But why do they still exist when the button is pressed? I mean, I thought variables declared with let inside a loop only exist inside that loop. Then why after the loop ends, and the button gets clicked, those ten different i variables still can be accessed by the event handler?

Or is it that the function in the event handler gets a hard-coded value in the code, like

"button" + 5 + "has been pressed";

I don't get that part. Thanks!

Steven Parker I really understand your answers :D

1 Answer

Steven Parker
Steven Parker
227,141 Points

:bell: Hi, I got alerted by your tag.

As I understand it, a variable is only disposed of when all scopes it is available to cease to exist. While the loop itself may have completed, the loop created a handler function to which the variable is still available, so it continues to exist for that function.