PHP Loops
PHP Loops are use to repeat a block of code again and again up to specified number of times or infinite. In PHP, there are 4 types of loops available. They are:
PHP For loop
PHP for loop is divided into 3 parts i.e. initialization, condition and increment/decrement. Initialization is the initial value from where the loop start its execution, condition specifies the ending value of loop, if condition is true it will execute, increment/decrement will change the variable value for the next condition.
Example 1: Write a PHP program to print counting 1 to 5 using for loop
<?php
for( $i=1; $i<=5; $i++ )
{
echo "<p>For Loop $i</p>" ;
}
?>
For Loop 2
For Loop 3
For Loop 4
For Loop 5
PHP While loop
PHP While loop is also used to repeat a block of code up to a certain number of times, but the syntax is different, initialization statement is defined before the while loop begins, condition appears same as in for loop, and increment/decrement statement appears inside the while loop.
Example 2: Write a program in PHP to print counting 1 to 5 using while loop
<?php
$i=1;
while($i<=5)
{
echo "<p>While Loop $i</p>";
$i++;
}
?>
While Loop 2
While Loop 3
While Loop 4
While Loop 5
PHP Do While Loop
PHP Do...while loop is also used to repeat a block of code up to a certain number of times, but the syntax is different, initialization statement is defined before the loop begins, increment/decrement will appear inside the do while loop and condition appears in the last.
Example 3: WAP to print counting 1 to 5 using Do While Loop
<?php
$i=1;
do
{
echo "<p>Do While Loop $i</p>";
$i++;
}while($i<=5);
?>
Do While Loop 2
Do While Loop 3
Do While Loop 4
Do While Loop 5
PHP foreach loop will be discuss after arrays, later in this tutorial.
Exercise Questions: Loops
- Create Image Gallery
<?php
for($i=1;$i<=3;$i++)
{
echo "<div class='col-md-4'>
<img src='$i.jpg'>
</div>";
}
>?
<?php
$file = glob("images/*.jpg");
//$file = glob("images/*");
$total = count($file);
for($i=1; $i<=$total; $i++)
{
echo "<img src='images/$i.jpg'>";
//$a = readdir(opendir('images'));
//echo "File = $a<br>";
//$b = opendir("images");
//$a = readdir($b);
//echo "File = $a<br>";
}
>?
<?php
echo "image gallery";
$b = opendir("images");
while($a = readdir($b))
{
if($a!='.' || $a!='..')
echo "<img src='images/$a'>";
}
>?
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