A for loop is used to repeatedly execute a block of code. It can be set to repeat a certain amount of times or until a certain condition is met.

The general format is as follows:

for (startValue; endCondition; increment)

{

code to be executed;

}

Example:

We want to echo the numbers from 1 to 5.

for ($i=1; $i <= 5; $i++)

{

echo $i."<br>";

}

This for loop sets up a variable $i and gives it a value of 1 to start. We then set the condition part of the for loop to say that the loop must stop as soon as $i is less than or equal to 5. The $i++ increments the value of $i by 1 each time the loop runs. So $i changes in value from 1 to 2 to 3 to 4 and lastly to 5 after which the loop ends. The echo statement echos the possible $i values as the loop ran. So, therefore the above code will output:

1
2
3
4
5