Why does this gives me the value exceeding the termination condition in javascript?

Asked Aug 11 '17 at 10:20

Active Aug 11 '17 at 10:28

Viewed 25 times

for (var i=1; i<=5; i++) {
  setTimeout( function timer(){
    console.log( i );
  }, i*1000 );
}

Even if the function passed to setTimeout as an argument doesn't create a new scope, being an entry controlled loop, why does the above code output to 6 & not 5 for each iteration ?

edited Aug 11 '17 at 10:28

asked Aug 11 '17 at 10:20

Dev P

Because `i` is incremented in the last iteration of for loop. – Shubham Aug 11 '17 at 10:23
Because the "i++" incrementation is executed – Samuil Petrov Aug 11 '17 at 10:23
because `i` is later evaluated, then the timeout is called. – Nina Scholz Aug 11 '17 at 10:25
But isn't 'for' an entry controlled loop which shouldn't bring the flow of control into the iteration for terminating condition? – Dev P Aug 11 '17 at 10:31
`i` is incremented (becoming `6`) **before** the `i <= 5` check is done, which is why that check fails and the loop is exited. – Aug 11 '17 at 10:32
Aha... Thanks @torazaburo – Dev P Aug 11 '17 at 10:37

Why does this gives me the value exceeding the termination condition in javascript?

0 Answers0