Can anyone explain what is happening here?
for (var i = 0; i < 10; i++) {
/* ... */
}
console.log(i);
//expect 9 as loop states i < 10, however it shows 10
I would expect when i is logged that it would show a value of 9. From what I understand is that the loop will run from 0-9 and then will stop as the loop states that i < 10. However, when I console.log(i) it shows 10. Can anyone explain why this is the case?
The increment happens before the last check.
In other words, the loop ends if and only if i >= 10, so it follows that after the loop ends, i must be at least 10.
The loop happens like this:
Set var i = 0;
Check if i < 10 (true), execute loop.
Execute i++.
Repeat step 2 and 3 until i < 10 is false (in this case, until i = 10).
What you have,
for (var i = 0; i < 10; i++) {
/* ... */
}
console.log(i); // logs 10
Can be re-written as a while
var i = 0;
while (i < 10) {
/* ... */
i++;
}
console.log(i); // logs 10
And now we see that at the end of i === 9 there is one last increment made so i === 10, causing the condition to fail thus exiting the loop.
Because the loop exits when it is not less than 10. i.e. when i == 10
The order of operation of the following for loop:
for(a;b;c) {
d;
}
Is this:
A, repeat(b, d, c) while b==true
Where the last statement called is b. This means that the statement just before b is c
do..while and not a while. Just write it as a regular while
That loops runs until i = 10, then stops. You are then console logging the 10.
whileloop and you'll see what is happening