PHP LOOP
PHP Looping
Looping statements in PHP are used to execute the same block of code a specified number of times.
PHP Looping
Very often when you write code, you want the same block of code to run a number of times. You can use looping statements in your code to perform this.
In PHP we have the following looping statements:
- while - loops through a block of code if and as long as a specified condition is true
- do...while - loops through a block of code once, and then repeats the loop as long as a special 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 Statement
The while statement will execute a block of code if and as long as a condition is true.
Syntax
| while ( condition ) code to be executed ; |
Example
The following example demonstrates a loop that will continue to run as long as the variable i is less than, or equal to 5. i will increase by 1 each time the loop runs:
<html> <body>
<?php $i=1; while($i<=5) { echo "The number is " . $i . "<br />"; $i++; } ?>
</body> </html> |
The do...while Statement
The do...while statement will execute a block of code at least once - it then will repeat the loop as long as a condition is true.
Syntax
| do { code to be executed; } while ( condition ); |
Example
The following example will increment the value of i at least once, and it will continue incrementing the variable i as long as it has a value of less than 5:
<html> <body>
<?php $i=0;
do { $i++; echo "The number is " . $i . "<br />"; }
while ($i<5);
?> </body> </html> |
The for Statement
The for statement is used when you know how many times you want to execute a statement or a list of statements.
Syntax
| for ( initialization ; condition ; increment ) { code to be executed; } |
Note: The for statement has three parameters. The first parameter initializes variables, the second parameter holds the condition, and the third parameter contains the increments required to implement the loop. If more than one variable is included in the initialization or the increment parameter, they should be separated by commas. The condition must evaluate to true or false.
Example
The following example prints the text "Hello World!" five times:
<html> <body>
<?php for ($i=1; $i<=5; $i++) { echo "Hello World!<br />"; } ?>
</body> </html> |
The foreach Statement
The foreach statement is used to loop through arrays.
For every loop, the value of the current array element is assigned to $value (and the array pointer is moved by one) - so on the next loop, you'll be looking at the next element.
Syntax
| foreach ( array as value ) { code to be executed; } |
Example
The following example demonstrates a loop that will print the values of the given array:
<html> <body>
<?php $arr=array("one", "two", "three");
foreach ($arr as $value)
{ echo "Value: " . $value . "<br />"; } ?>
</body> </html> |
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