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 will execute a block of code if and as long as a condition is true.
Syntax
while (condition) |
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> <?php </body> |
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 |
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> <?php </body> |
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) |
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> <?php </body> |
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 $value (and the array pointer is moved by one) - so on the next loop, you'll be looking at the next element.
Syntax
foreach (array as value) |
Example
The following example demonstrates a loop that will print the values of the given array:
<html> <?php foreach ($arr as $value) </body> |
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