CODEWITHSUNDEEP
javascript
hasExams
hasExams

Reputation: 205

why does statement below loop executes before termination of loop

I was wondering why do i get alert before printing all vlaues 

<script>
    for(var i=0; i<=1000; i++)
    {
        console.log(i);
    }
    alert('Hello');
</script>

Upvotes: 2

Views: 114

Answers (5)

check123
check123

Reputation: 2009

<script>
INSTRUCTION A;
INSTRUCTION B;
INSTRUCTION C;
</script>

In javascript the execution of INSTRUCTION B is not dependent upon completion of A and similarly for C.

You may want to try something like: 

var test = 0;
var i=0;
while(test!=1) {
  console.log(i);
  i++;
  if(i==1000) {
    alert("Hi!");
    test=1;
  }
}

Upvotes: 0

alex
alex

Reputation: 490461

alert() will block your browser whilst waiting to be dismissed by the user.

Maybe they haven't been written to the console yet by the time the alert appears. It depends on what your console object is.

BTW, they appear fine in the console before the alert in my Chrome 10 on OS X.

Upvotes: 1

KooiInc
KooiInc

Reputation: 122956

The console is lagging behind. The loop is executed first. This shows it better:

var t = [];
for(var i=0; i<=1000; i++)
{
    t.push(i);
}
console.log(t.length);
alert('Hello');

Upvotes: 1

Daniel Lubarov
Daniel Lubarov

Reputation: 7924

How are you executing this? My console doesn't show the alert until all the numbers are displayed. Yours must be lazily rendering output. So the loop does finish before the alert, but the log was only written to a buffer.

Upvotes: 0

Akash Kava
Akash Kava

Reputation: 39946

Well it is not executing before loop, it is executing correctly.

Your console may be refreshing little late.

Upvotes: 3

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