PHP Loops - ashish9342/FreeCodeCamp GitHub Wiki
Loops are blocks of code that execute a specified number of times. Using loops reduces the number of lines of code.
PHP works with 4 different types of loops:
- While loop
- Do...while loop
- For loop
- Foreach loop
The while
loop continues to excecute as long as the specified condition is true.
<?php
while(condition is true)
{
execute code;
}
?>
Example:
<?php
$x = 1;
while($x <= 3)
{
echo "x=$x ";
$x++;
}
?>
Output:
x=1 x=2 x=3
In the do...while
loop the block of code is executed before the condition is checked.
<?php
do {
execute code;
} while (condition);
?>
Example:
<?php
$x= 1;
do {
echo "x=$x ";
$x++;
} while ($x < 5);
?>
Output:
x=1 x=2 x=3 x=4
The for
loop is used when the number of times the block is to be executed is known in advance.
<?php
for (variable initialisation; test condition; increment)
{
execute code;
}
?>
Example:
<?php
for ($x=1 ; $x <= 4 ; $x++)
{
echo "x= $x ";
}
?>
Output:
x=1 x=2 x=3 x=4
The foreach
loop helps in traversing through arrays.
<?php
foreach ($array as $value)
{
executable code;
}
?>
Example:
<?php
$numbers= array("One", "Two", "Three");
foreach ($numbers as $value)
{
echo "$value ";
}
?>
Output:
One Two Three