php 循环if

<?php
// for循环示例
for ($i = 0; $i < 5; $i++) {
    echo "循环次数: " . $i . "\n";
}

// foreach循环示例
$fruits = array("苹果", "香蕉", "橙子");
foreach ($fruits as $fruit) {
    echo "水果: " . $fruit . "\n";
}

// while循环示例
$count = 0;
while ($count < 5) {
    echo "计数: " . $count . "\n";
    $count++;
}

// do...while循环示例
$count = 0;
do {
    echo "至少执行一次: " . $count . "\n";
    $count++;
} while ($count < 5);

// if语句示例
$age = 25;
if ($age >= 18) {
    echo "成年人\n";
}

// if...else示例
if ($age >= 18) {
    echo "成年人\n";
} else {
    echo "未成年人\n";
}

// if...elseif...else示例
if ($age < 13) {
    echo "儿童\n";
} elseif ($age < 18) {
    echo "青少年\n";
} else {
    echo "成年人\n";
}
?>

// 错误的for循环示例
for ($i = 0; $i <= 5; $i++) { // 应该是 < 5
    echo "循环次数: " . $i . "\n";
}

// 错误的if语句示例
$age = 25;
if ($age > 18) { // 应该是 >= 18
    echo "成年人\n";
}