switch语句 php

switch (expression) {
    case label1:
        code_to_be_executed1;
        break;

    case label2:
        code_to_be_executed2;
        break;

    ...
    
    default:
        default_code_to_be_executed;
 }

$day = 'Monday';

switch ($day) {
    case 'Monday':
        echo "Today is Monday.";
        break;
    case 'Tuesday':
        echo "Today is Tuesday.";
        break;
    case 'Wednesday':
        echo "Today is Wednesday.";
        break;
    default:
        echo "Unknown day.";
}

$day = 'Monday';

switch ($day) {
    case 'Monday':
        echo "Today is Monday.";
        // 没有break，会继续执行下一个case
    case 'Tuesday':
        echo "Today is Tuesday.";
        break;
    default:
        echo "Unknown day.";
}

Today is Monday.Today is Tuesday.

$day = 'Sunday';

switch ($day) {
    case 'Monday':
        echo "Today is Monday.";
        break;
    case 'Tuesday':
        echo "Today is Tuesday.";
        break;
    default:
        echo "Unknown day.";
}

Unknown day.