1.2.1187. Switch Without Default

Always use a default statement in switch() and match().

Switch statements hold a number of ‘case’ that cover all known situations, and a ‘default’ one which is executed when all other options are exhausted.

For Match statements, a missing default will lead to the UnhandledMatchError` exception being raised. On the other hand, the switch statement will simply exit without action nor alert. Most of the time, switch() do need a default case, so as to catch the odd situation where the ‘value is not what it was expected’. This is a good place to catch unexpected values, to set a default behavior.

<?php

// Missing default
switch($format) {
    case 'gif' :
        processGif();
        break 1;

    case 'jpeg' :
        processJpeg();
        break 1;

    case 'bmp' :
        throw new UnsupportedFormat($format);
}
// In case $format is not known, then switch is ignored and no processing happens, leading to preparation errors


// switch with default
switch($format) {
    case 'text' :
        processText();
        break 1;

    case 'jpeg' :
        processJpeg();
        break 1;

    case 'rtf' :
        throw new UnsupportedFormat($format);

    default :
        throw new UnknownFileFormat($format);
}
// In case $format is not known, an exception is thrown for processing

?>

See also UnhandledMatchError.

1.2.1187.1. Connex PHP features

1.2.1187.1.1. Suggestions

  • Add a default case

  • Catch the UnhandledMatchError exception

1.2.1187.1.2. Specs

Short name

Structures/SwitchWithoutDefault

Rulesets

All, Analyze, CE, CI-checks, Changed Behavior

Exakat since

0.8.4

PHP Version

All

Severity

Major

Time To Fix

Quick (30 mins)

Precision

Very high

ClearPHP

no-switch-without-default

Examples

Zencart, Traq

Available in

Entreprise Edition, Community Edition, Exakat Cloud