With a PHP loop, you can run the same block of code a certain number of times. PHP has the following four types of loops.
For: for makes a block of code run through itself a certain number of times.
While: while runs a block of code over and over again as long as a certain condition is true.
do…while : do while goes through a block of code once and then repeats the loop as long as a special condition is true.
foreach : foreach repeats a block of code for every item in an array.
We’ll talk about the continue and break keywords, which are used to control how loops work.
For loop
When you know how many times you want to run a statement or a block of statements, you use the for statement.
PHP’s for loop Syntax
for (initialization; condition; increment){
code to be executed;
}
The initializer is used to set the number of loop iterations counter’s starting value. For this, you can declare a variable, and the usual name for it is $i.
Example
The code in the next example loops five times and changes the value of two variables each time through the loop.
<html>
<body><?php
$x= 0;
$y= 0;for( $i = 0; $i<10; $i++ ) {
$x += 5;
$y += 2;
}echo (“At the end of the loop x = $x and y = $y” );
?></body>
</html>
Output
At the end of the loop x = 50 and y = 20
while loop statement
If and for as long as a test expression is true, a block of code will be executed by the while statement.
The code block will be performed if the test expression is true. The test expression will again be evaluated after the code has run, and the loop will keep going until it is determined that the test expression is false.
PHP’s While loop Syntax
while (condition) {
code to be executed;
}
Example
On each loop iteration in this example, a variable’s value is decreased, and the counter increases until it hits 10, at which point the evaluation is false and the loop is terminated.
<html>
<body><?php
$a = 0;
$numbr = 100;while( $a< 10) {
$numbr –;
$a++;
}echo (“Loop stopped at a = $a and number = $numbr ” );
?></body>
</html>
Output
This will lead to the outcome shown below.
At a = 10 and number = 90, the loop halted.
do…while loop Statement
If a condition is true, the do…while statement will run a block of code at least once before repeating the loop.
Syntax
do {
code to execute;
}
while (condition);
Example
The example that follows will increase the value of I at least once and keep increasing it until it reaches a value lower than 10 Live Demo
<html>
<body><?php
$a = 0;
$number = 0;do {
$a++;
}while( $a< 15 );
echo (“Loop stopped at a = $a” );
?></body>
</html>
Output
This will lead to the outcome shown below.
Loop halted at index 15
The foreach loop statement
To loop around an array, use the foreach command. The array pointer is shifted one position for each pass, and the value of the current array element is assigned to $value. The following pass will process the next element.
Syntax
foreach (array as value) {
code to be executed;
}
Example
Try the example in the following to list the values of an array.
<html>
<body><?php
$array = array( 1, 2, 3, 4, 5,6,7,8,9);foreach( $array as $val ) {
echo “Value is $val <br />”;
}
?></body>
</html>
Output
This will lead to the outcome shown below.
Value is 1
Value is 2
Value is 3
Value is 4
Value is 5
Value is 6
Value is 7
Value is 8
Value is 9
The break Statement
To end the execution of a loop early, use the PHP break keyword.
The statement block contains the break statement. You have complete control over it, and you can leave the loop at any time. An immediate statement to the loop will be executed after exiting the loop.
Break Statement PHP Example
When the counter value hits 3 and the loop closes, the condition test in the example below becomes true.
<html>
<body><?php
$k = 0;while( $k< 10) {
$k++;
if( $k == 5 )break;
}
echo (“Loop stopped at k = $k” );
?></body>
</html>
Result
Loop stopped at i = 3
The continue statement
While it stops the current iteration of a loop, the PHP continue keyword does not end the loop.
The continue statement follows a conditional test and is positioned inside the statement block that contains the code that the loop performs, just as the break statement. The remainder of the loop code is skipped for passes that come across continue statements, and the subsequent pass begins.
Continue Statement PHP Example
The loop in the following example shows the contents of the array, but when the condition is met, it simply skips the relevant code and produces the next item.
<html>
<body><?php
$array = array( 0,1, 2, 3, 4, 5);foreach( $array as $val) {
if( $val == 2 )continue;
echo “Value is $val <br />”;
}
?></body>
</html>
Output
This will lead to the outcome shown below.
Value is 0
Value is 1
Value is 2
Value is 4
Value is 5