PHP switch Statement
The PHP switch statement is used to perform different actions based on different conditions.
The PHP switch Statement
Use the switch statement to select one of many blocks
of code to be executed.
Syntax
switch (expression) {
case label1:
//code block
break;
case label2:
//code block;
break;
case label3:
//code block
break;
default:
//code block
}
This is how it works:
- The expression is evaluated once
- The value of the expression is compared with the values of each case
- If there is a match, the associated block of code is executed
- The
breakkeyword breaks out of the switch block - The
defaultcode block is executed if there is no match
Example
$favcolor = "red";
switch ($favcolor) {
case "red":
echo "Your favorite color is red!";
break;
case "blue":
echo "Your favorite color is blue!";
break;
case "green":
echo "Your favorite color is green!";
break;
default:
echo "Your favorite color is neither red, blue, nor green!";
}
The PHP break Keyword
When PHP reaches a break keyword, it breaks out of the switch block.
This will stop the execution of more code, and no more cases are tested.
The last block does not need a break, the block breaks (ends) there anyway.
Warning:
If you omit the break statement in a case that
is not the last,
and that case gets a match,
the next case will also be executed even if the evaluation does not match the case!
Example
What happens if we remove the
break statement
from case "red"?
$favcolor is red, so the code block from case "red" is executed,
but since it has no break statement, the code block from case "blue"
will also be executed:
$favcolor = "red";
switch ($favcolor) {
case "red":
echo "Your favorite color is red!";
case "blue":
"Your favorite color is blue!";
break;
case "green":
echo "Your favorite color is green!";
break;
default:
echo "Your favorite color is neither red, blue, nor green!";
}
The PHP default Keyword
The PHP default keyword specifies the code to run if there is no
case match:
Example
If no cases get a match, the
default block
is executed:
$d = 4;
switch ($d) {
case 6:
echo "Today is Saturday";
break;
case 0:
echo "Today is Sunday";
break;
default:
echo "Looking forward to the Weekend";
}
The default case does not have to be the last case in a switch
block:
Example
Putting the default block elsewhere than
at the end of the break block is allowed, but not recommended.
$d = 4;
switch ($d) {
default:
echo "Looking forward to the Weekend";
break;
case 6:
echo "Today is Saturday";
break;
case 0:
echo "Today is Sunday";
}
Note: If
default is not the last
block in the break block,
remember to end the default block with a
break statement.
Common Code Blocks
If you want multiple cases to use the same code block, you can specify the cases like this:
Example
More than one case for each code block:
$d = 3;
switch ($d) {
case 1:
case 2:
case 3:
case 4:
case 5:
echo "The weeks feels so long!";
break;
case 6:
case 0:
echo "Weekends are the best!";
break;
default:
echo "Something went wrong";
}
