PHP - Switch

The Switch statement in PHP language is used to execute one of many code statements. It can be considered as group of if-else statements.

Syntax

 switch (expression){ case 1: statement 1; break; case 2: statement 2; break; ... ... ... case N: statement N; break; default: default statement; } 

The Switch expression is evaluated and matched with the cases. When Case matches, the following block of code is executed.

Flow Diagram:

Example:

In the example below, the switch expression is a variable called i with value 2 which is matched against case values. When the case value matches with expression value, the following block of code is executed.

 <?php $i = 2; switch($i){ case 1: echo "Red\n"; break; case 2: echo "Blue\n"; break; case 3: echo "Green\n"; } ?> 

The output of the above code will be:

 Blue 

default and break statements

Default case and break statement are optional here.

• Default Case: Default Statement is executed when there is no match between switch expression and test cases.
• Break Statement: Break statement is used to get out of the Switch statement after a match is found.

Example:

In the example below, the switch expression is a variable called i with value 10 which is matched against case values. As there is no case that matches with value 10, hence default block of code gets executed.

 <?php $i = 10; switch($i){ case 1: echo "Red\n"; break; case 2: echo "Blue\n"; break; case 3: echo "Green\n"; break; default: echo "No match found.\n"; } ?> 

The output of the above code will be:

 No match found. 

Please note that, the default statement can be placed at any position in the switch statement. In such instances, add break statement with default statement.

Example:

Consider the example below, where default statement is placed on the top in a switch statement.

 <?php $i = 10; switch($i){ default: echo "No match found.\n"; break; case 1: echo "Red\n"; break; case 2: echo "Blue\n"; break; case 3: echo "Green\n"; } ?> 

The output of the above code will be:

 No match found. 

Common code blocks

There are instances where same code block is required in multiple cases.

Example:

In the example below, same code block is shared for different switch cases.

 <?php $i = 10; switch($i){ case 1: echo "Red\n"; break; case 2: case 10: echo "Blue\n"; break; case 3: case 4: case 5: echo "Green\n"; } ?> 

The output of the above code will be:

 Blue