The switch statement

PHP course · Beginner · Lesson 38/116

Learn multi-way selection with switch, case, break and default.

The switch statement

To branch on many possible values of a single variable, use switch. You write switch ($day) and list each possible value with case. Code runs from the matching case onward.

Key detail: without a break; at the end of a case, PHP falls through to the next case (called fall-through). When no case matches, default runs.

break and fall-through

When a case matches, PHP starts running code from that point. When it sees break; it exits the switch. Without break; the code of later cases also runs; this is called fall-through.

Sometimes fall-through is what you want (for example two values producing the same output). But most of the time you put a break; in each case to prevent unintended execution.

Exercise Print the day name

The $day variable is already declared. Write a switch: for case 1 print 'Monday', for case 2 print 'Tuesday', for default print 'Unknown'. Put a break; at the end of each case.

Show example solution

... break; structure.
Example solution:
<?php
$day = 1;
// Day name
switch ($day) {
  case 1:
    echo 'Monday';
    break;
  case 2:
    echo 'Tuesday';
    break;
  default:
    echo 'Unknown';
}

Test yourself

What is the switch output?

$color = 'red';
switch ($color) {
  case 'blue':
    echo 'sky';
    break;
  case 'green':
    echo 'grass';
    break;
  default:
    echo 'unknown';
}

sky
grass
red
unknown

Show answer

unknown — Correct. 'red' is not in the case list, so default runs.

Write the break keyword

$n = 2;
switch ($n) {
  case 1:
    echo 'one';
    ____;
  case 2:
    echo 'two';
    break;
}

Show answer

$n = 2;
switch ($n) {
  case 1:
    echo 'one';
    break;
  case 2:
    echo 'two';
    break;
}

Match the switch parts

switch

Branching statement
case

Possible value
break

Exit command
default

Catcher branch

The switch statement