Loops in PHP?
Often when you write code, you want the same block of code to run over and over again in a row. Instead of adding several almost equal lines in a script we can use loops to perform a task like this.
In PHP, we have the following looping statements:
- while -loops through a block of code while a specified condition is true
- do...while - loops through a block of code once, and then repeats the loop as long as a 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
The while Loop
The while loop executes a block of code while a condition is true.
Syntax
while (
condition)
{
code to be executed;
}
Example:
<html>
<body>
<?php
$i=1;
while($i<=5)
{
echo "The number is " . $i . "<br />";
$i++;
} ?>
</body>
</html>
Click to see output
The do...while Statement
The do...while statement will always execute the block of code once, it will then check the condition, and repeat the loop while the condition is true.
Syntax
do
{
code to be executed;
}
while (
condition);
Example:
<html>
<body>
<?php
$i=1;
do
{
$i++;
echo "The number is " . $i . "<br />";
}
while ($i<=5);
?>
</body>
</html>
Click to see output
PHP Looping - For Loops
The for Loop
The for loop is used when you know in advance how many times the script should run.
Syntax
for (
init; condition; increment)
{
code to be executed;
}
Example:
<html>
<body>
<?php
for ($i=1; $i<=5; $i++)
{
echo "The number is " . $i . "<br />";
}
?>
</body>
</html>
Click to see output
The foreach Loop
The foreach loop is used to loop through arrays.
Syntax
foreach ($
array as$
value)
{
code to be executed;
}
Example:
<html>
<body>
<?php
$x=array("one","two","three");
foreach ($x as $value)
{
echo $value . "<br />";
}
?>
</body>
</html>
Click to see output