What does this javascript code does? i don't understand it. Thanks

[hectorespresati]

<script>
var sum = 0;
for (fl=10; fl<=150; fl = fl + 5)
{
sum = sum + fl;
}
document.write (sum = sum + fl);
</script>

[George88]

http://jsfiddle.net/DZh2Y/

The script is a for loop. The loop parameters are as follows:

1. Declaration & initialisation
2. Logical check
3. Increment/decrement

In other words, the 1st parameter of the loop declares and initialises a variable (fl) to 10. The loop then executes the 2nd parameter, which is a logical check. It basically says "if FL is less-than-or-equal-to 150". If this statement is a true statement, it will execute the body of the loop (sum = sum + fl) and will then proceed to the 3rd and final parameter of the loop, which is an increment.

This code can also be written as:

var sum = 0;
for (fl=10; fl<=150; fl+= 5)
{
    sum += fl;
}
document.write (sum += fl);

This code doesn't really make much sense, but it may be part of a larger file that we can't see.

[sumanthan]

If you run the script the output would be 2475

for (fl = 10; fl <= 150; fl = fl + 5) This means that you give the value to fl =10 and to add 5 as long as fl value<=150

that means fl = 10,15,20,25.........155

when you have sum=0 that means new sum=0+10, sum=10+15, sum=25+20, sum=55+25

and finally the new sum would be 2475

I think this one ill clearly you question.