PHP Loops


title: Loops

PHP Loops

When you need to repeat a task multiple times, you can use a loop instead of adding the same code over and over again.
PHP has the following loop statements :

  • for – loop through a block of code with specific number of times.
  • while – loop through a block of code if condition is true.
  • do…while – loop through a block of code one and continue loop if condition is true.
  • foreach – loop through a block of code for each value within an array.

Using a break within the loop can stop the loop execution.

For loop

Loop through a block of code with specific number of times.

Syntax

for (init counter; condition; counter increment or decrement) { // Code to be executed }

Example

<?php for($index = 0; $index < 5; $index ++) { echo "Current loop counter ".$index.".\n"; } ?>

Output

> Current loop counter 0. > Current loop counter 1. > Current loop counter 2. > Current loop counter 3. > Current loop counter 4.

While loop

Loop through a block of code if condition is true.

Syntax

while (condition) { // Code to be executed }

Example

<?php $index = 10; while ($index >= 0) { echo "The index is ".$index.".\n"; $index--; } ?>

Output

> The index is 10. > The index is 9. > The index is 8. > The index is 7. > The index is 6. > The index is 5. > The index is 4. > The index is 3. > The index is 2. > The index is 1. > The index is 0.

Do…While loop

Loop through a block of code once and continue to loop if the condition is true.

Syntax

do { // Code to be executed } while (condition);

Example

<?php $index = 3; do { // execute this at least 1 time echo "Index: ".$index.".\n"; $index --; } while ($index > 0); ?>

Output

> Index: 3. > Index: 2. > Index: 1.

Foreach loop

Loop through a block of code for each value within an array.

Syntax

foreach ($array as $value) { // Code to be executed }

Example

<?php $array = ["Ali", "Ah Kao", "Muthu", "Gwen", "Lucida", "Cecily", "Arthur", "Flora"]; foreach ($array as $name) { echo "Hi, my name is ".$name.".\n"; if ($name == "Cecily") { echo "\"Hello, ".$name."!\""; // stop the loop if name is Cecily break; } } ?>

Output

> Hi, my name is Ali. > Hi, my name is Ah Kao. > Hi, my name is Muthu. > Hi, my name is Gwen. > Hi, my name is Lucida. > Hi, my name is Cecily. > "Hello, Cecily!"

For More Information:

http://php.net/manual/en/control-structures.for.php

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