PHP Loops
Loops are used to execute the same block of code again and again, as long as a certain condition is true.
In PHP, we have the following loop types:
- while – loops through a block of code as long as the specified condition is true.
- do…while – loops through a block of code once, and then repeats the loop as long as the specified condition is true.
- for – loops through a block of code a specified number of times.
- foreach – loops through a block of code for each element in an array.
- while loop: This loop executes a block of code as long as the specified condition is true. The syntax for the while loop is as follows:
while (condition) {
code to be executed;
}
The example below displays the numbers from 1 to 5 using while loop:
<?php
$i = 1;
while ($i <= 5) {
echo "The number is: $i <br>";
$i++;
}
?>
Output:-
The number is: 1
The number is: 2
The number is: 3
The number is: 4
The number is: 5
2. do…while loop: This loop executes a block of code once, and then repeats the loop as long as the specified condition is true. The syntax for the do…while loop is as follows:
do {
code to be executed;
} while (condition);
Example of do..while loop-:
<?php
$i = 1;
do {
echo "The number is: $i <br>";
$i++;
} while ($i <= 5);
?>
Output:-
The number is: 1
The number is: 2
The number is: 3
The number is: 4
The number is: 5
3. for loop: This type of loops is used when the user knows in advance, how many times the block needs to execute. The syntax for the for loop is as follows:
for (init counter; test counter; increment counter) {
code to be executed for each iteration;
}
Parameters:
init counter: Initialize the loop counter value
- test counter: Evaluated for each loop iteration. If it evaluates to TRUE, the loop continues. If it evaluates to FALSE, the loop ends.
- increment counter: Increases the loop counter value
Example of for loop-:
<?php
for ($x = 0; $x <= 5; $x++) {
echo "The number is: $x <br>";
}
?>
Output:-
The number is: 1
The number is: 2
The number is: 3
The number is: 4
The number is: 5
4. foreach loop: This loop is used to iterate over arrays. The syntax for the foreach loop is as follows:
foreach ($array as $value) {
//code to be executed;
}
Here’s an example of a foreach loop that prints each element in an array:
<?php
$colors = array("red", "green", "blue", "yellow");
foreach ($colors as $value) {
echo "$value <br>";
}
?>
Output-:
red
green
blue
yellow
