Unhandled Match Value

Why This Happens

PHP 8.0's match expression is strict and exhaustive. Unlike switch, if no arm matches the given value and there is no default arm, PHP throws UnhandledMatchError. This is actually a safety feature that catches missing cases at runtime.

The Problem

function statusLabel(string $status): string {
    return match ($status) {
        'active' => 'Active',
        'inactive' => 'Inactive',
    };
}
echo statusLabel('pending'); // No matching arm

The Fix

function statusLabel(string $status): string {
    return match ($status) {
        'active' => 'Active',
        'inactive' => 'Inactive',
        'pending' => 'Pending',
        default => 'Unknown',
    };
}

Step-by-Step Fix

1. 1

   Identify the unmatched value

   Check what value was passed to the match expression. Add logging or inspect the variable before the match.

2. 2

   Add the missing case

   If the value is a legitimate case, add a new arm to the match expression to handle it.

3. 3

   Add a default arm

   Add a default arm to handle unexpected values gracefully, either returning a fallback or throwing a descriptive exception.