Question

Look at this code

var count = 0, count2 = 0
setInterval(function() {
    // I wrote this on two lines for clarity.
    ++count;
    count2 = count;
}, 1000);
if(count2==5)
{
alert('testing script')
}

How come the if statement does not execute when count2 = 5

Answer 1

The problem is: First you only define the logic for the interval and then you check the count2 variable. But in that context the variable has still the value 0.

Each time the interval is fired (and in most cases it is after the if-check), only the part inside the function() { } block is executed

function() {
    // I wrote this on two lines for clarity.
    ++count;
    count2 = count;
}

and it is not continued to the if statement because it is not part of the interval logic.

The first idea I have is to put the if statement into the function() { } block like this:

var count = 0, count2 = 0;

setInterval(function() {

    // I wrote this on two lines for clarity.
    ++count;
    count2 = count;

    if(count2 == 5)
    {
        alert('testing script');
    }

}, 1000);