Introduction
PHP For Loop is of two types:
- For Loop
- Foreach Loop
Description
PHP For Loop is used to initialize a variable, check condition and increment (or) decrement the variable. All these three functions are declared in a single statement and can be repeated as per requirement.
1)
Initialization : In initialization section, the variables are declared and initialized. Initialization will be executed only once and if it satisfies it goes to condition section.
2)Condition : In condition section, the condition is checked. If true, then control enters the loop and the statements are executed.Then the control goes to increment section. But if the condition is false, the loop is terminated.
3)Increment or Decrement : Once the loop gets executed the flow of control jumps back to Increment or Decrement section. Here the value gets incremented (or) decremented and again the control goes to condition section. This section is optional. Syntax
Example
[php]
<!DOCTYPE html>
<html>
<body>
<?php
for ($x = 0; $x <= 30; $x++) {
echo "X Value is: $x <br>";
}
?>
</body>
</html>
[/php]
Output:
Description
Using foreach loop, a block of statements can be repeated over
arrays. foreach works only on arrays. Syntax
There are two types of syntax
[php]
//Syntax_1
foreach ($array as $value){
statement;
}
//Syntax_2
foreach ($array as $key => $value){
statement;
}
[/php]
Example
[php]
<!DOCTYPE html>
<html>
<body>
<?php $arr = array("John", "Mike", "Henry", "Albert");
foreach ($arr as $key => $value)
{
echo "Key: $key;
Value: $value <br>";
}
foreach ($arr as $value)
{
echo "$value ";
}
?>
</body>
</html>
[/php]
Output:
Key Points
- For loop initializes variables, checks condition and increments/decrements. This can be used when there is sequential input/output.
- For each loop is applicable to arrays only.