Then we’ve got the for loop. This loop is in some point of view kind of smilar to the while loop as it as well repeats a certain code several times. Though, the for loop requires a variable to be set, an increment value (or decrement) and a condition, as argruments of the loop. A basic example of a for loop looks like this (structure) :
for ( set variable; condition; action increment/decrement ) {
...act code...
}
Say we want to set a begin value (we use the variable named $i, which is a common name for integer variables to be used) to 0 and we want to let it count to 10.
Example:
for ( $i = 0; $i <= 10; $i++ ) {
echo $i;
}
The variable set is $i, which we set to 0. The condition for the code to be ran is that $i is smaller than or equal to 10. So as long as this is the case, the value of $i will be shown on the screen (echo $i). Each time it shows $i on the screen, $i will be increased by 1 ($i++) and the loop will be repeated as long as the condition ($i<=10) is still true. In other words: it shows the value of $i on the screen, increases it by 1, shows it on the screen again, etc., and repeats this until $i is equal to 10.
Output:
1
2
3
4
5
6
7
8
9
10
You could also make it count downwards:
for ( $i = 10; $i => 0; $i--) {
echo $i;
}
You see we now set $i (begin value) to 10 and set the condition to $i is larger or equal to 0, and the action to repeat each time the loop is executed to $i--(which means: decrease $i by 1).
Admin.
Sat, Jan 16, 2010
PHP & MySql