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Philip Kroupoderov
Front End Web Development Techdegree Graduate 21,641 PointsQuestion about the less < comparison
The for loop says:
for(var i = 0; i < buttons.length; i++)
He has buttons 0 to 9, meaning buttons.length is equal to 10. So why is he getting an alert dialog saying that "button 10" is pressed (because i < buttons.length which is the same as i < 10 should be 0 to 9, so it should be saying that button 9 is pressed and not 10). I also saw that when using let it did solve this problem. Could someone please explain all this:).
1 Answer
Steven Parker
229,644 PointsWith "var", the loop variable "i" is a global. So it is shared by all of the button handlers. While the handlers are being set up, the value of "i" counts up from 0 and when it reaches 10, the loop stops.
But then later, when any of the handlers accesses the value of "i", it is 10. It's the same for any button.
By using "let", each handler gets it's own copy of "i", which remains the same as when the handler was set up.