PHP switch

The PHP switch Statement

Use the switch statement to choose one of several blocks of code to execute.

Syntax

switch (expression) {

  case label1:

    //code block

    break;

  case label2:

    //code block;

    break;

  case label3:

    //code block

    break;

  default:
    //code block
}

Here’s how it works:

1. The expression is evaluated once.
2. The value of the expression is compared with each case’s value.
3. If a match is found, the corresponding block of code is executed.
4. The break keyword exits the switch block.
5. The default block is executed if no match is found.

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 break Keyword

When PHP encounters a break keyword, it exits the switch block, stopping the execution of any additional code, and no further cases are evaluated.

The last block does not require a break, as the block naturally ends there.

Example

What happens if we remove the break statement from case “red”?

Since $favcolor is red, the code block for case “red” will execute, but without a break statement, the code block for case “blue” will also execute.

$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 default Keyword

The default keyword indicates the code to execute if no case matches.

Example

If none of the cases 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 need to be the final case in a switch block.

Example

Placing the default block anywhere other than at the end of the switch block is permitted, but not advisable.

$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";
}

Common Code Blocks

If you want multiple cases to execute the same code block, you can specify the cases as follows:

Example

Multiple cases 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";
}