1.2.1179. 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.

1.2.1179.1. Suggestions

• Add a default case

• Catch the UnhandledMatchError exception

1.2.1179.2. Specs

Short name	Structures/SwitchWithoutDefault
Rulesets	All, Analyze, CE, CI-checks
Exakat since	0.8.4
PHP Version	All
Severity	Major
Time To Fix	Quick (30 mins)
Precision	Very high
Features	match, switch, case, default
ClearPHP	no-switch-without-default
Examples	Zencart, Traq
Available in	Entreprise Edition, Community Edition, Exakat Cloud