PHP switch Statement

Updated: April 19th, 2022, 10:37:38 IST

Published: April 19th, 2022

A switch statement is similar to a series of IF statements on the same expression. In many cases, you may wish to compare the same variable (or expression) to a given set of values and execute a different piece of code based on which value it equals. This is exactly the objective of the switch statement.

switch Statement

Syntax

switch (n) {
  case label1:
    code to be executed if n=label1;
    break;
  case label2:
    code to be executed if n=label2;
    break;
  case label3:
    code to be executed if n=label3;
    break;
    ...
  default:
    code to be executed if n is different from all labels;
}

Here's how it works:

First, there is a single expression n (usually a variable) that is evaluated once.
The value of the expression is then compared to the values in the structure for each case.
If a match is found, the code associated with that case is performed.
Use break to prevent the code from automatically moving on to the next scenario.
If no match is discovered, the default statement is used.

Example #1

It's use is similar to elseif statement we can try both ways to execute the same output.

<?php
if ($i == 0) {
    echo "i equals 0";
} elseif ($i == 1) {
    echo "i equals 1";
} elseif ($i == 2) {
    echo "i equals 2";
}

switch ($i) {
    case 0:
        echo "i equals 0";
        break;
    case 1:
        echo "i equals 1";
        break;
    case 2:
        echo "i equals 2";
        break;
}
?>

Example #2

<?php
$favday = "friday";

switch ($favday) {
  case "monday":
    echo "My favorite day is monday!";
    break;
  case "tuesday":
    echo "My favorite day is tuesday!";
    break;
  case "friday":
    echo "My favorite day is friday!";
    break;
  default:
    echo "My favorite day is neither monday, tuesday, nor friday!";
}
?>

It should be noted that, unlike in some other languages, the continue statement applies to switch and functions similarly to the break statement. continue is used if you have a switch within a loop and want to continue to the next iteration of the outer loop.

Some important note on switch Statement:

To avoid errors, it is critical to understand how the switch statement is performed.
The switch statement is executed one line at a time (actually, statement by statement).
No code is performed at the beginning.
PHP begins executing the statements only when a case statement is found whose expression evaluates to a value that matches the value of the switch expression.
PHP executes the statements until the end of the switch block or the first time it encounters a break statement.
If you do not include a break statement at the end of a case's statement list, PHP will continue to execute the statements in the next case.