if else 条件语句 switch case 条件分支

if else 条件语句

<?php

if (false) {
    echo "Hello World!";
} else {
    echo "Hello PHP!";
}

if..elseif..else

<?php

if (true) {
    echo "Hello Java!";
} elseif (true) {
    echo "Hello PHP!";
} else {
    echo "Hello C++!";
}

switch..case

<?php

$n = 3;

switch ($n) {
    case 1:
        echo "今天星期一";
        break;
    case 2:
        echo "今天星期二";
        break;
    default:
        echo '今天星期天';
}