How to perform an action every 5 results?

Question

How can I perform an action within a `for` loop every 5 results? Basically I'm just trying to emulate a table with 5 columns.

Answer 1

You use the mod function on the loop counter.

THe remainder will be zero every 5 iterations...

for (mainLoop=0; mainLoop < N; mainLoop++)

{

....

if ((mainLoop % 5)==0)

{

//* PUT YOUR CODE IN HERE THAT EXECUTES EVERY 5th ITERATION *//

} //every 5th iteration

} //mainLoop

===============================================

the following table illustrates this pattern more clearly.

main loop counter remainder after dividing by 5

0 0

1 1

2 2

3 3

4 4

5 0

6 1

7 2

8 3

9 4

10 0

11 1

etc

Answer 2

Hello,

One option would be to use modular arithmetic. Modular arithmetic is basically looking at the remainder after dividing two integers and is typically denoted by '%' in programming languages. For example, 5%4 would give you 1 because five divided by four has a remainder of one. In our case, if we have some counter i, we want an action to occur whenever i % 5 ==0.

In PHP, this could look like:

for ($i=0; $i<16; $i++){

if ($i %5 == 0)

echo "hi";

}

which would print

hihihihi

where hi prints when i=0,5,10, and 15

Hope this helps,

Philip