PHP8在线教程文档

PHP数组综合示例

<?php
// 1. 索引数组示例

echo "<h4>1. 索引数组示例</h4>";

// 创建索引数组
$languages = array("PHP", "JavaScript", "Python", "Java", "C++");

// 访问数组元素
echo "第一个编程语言: " . $languages[0] . "<br>";
echo "第二个编程语言: " . $languages[1] . "<br>";

// 修改数组元素
$languages[2] = "Ruby";
echo "修改后的第三个编程语言: " . $languages[2] . "<br>";

// 添加新元素
$languages[] = "Go";
echo "数组的新长度: " . count($languages) . "<br>";
echo "最后添加的编程语言: " . end($languages) . "<br>";

// 遍历数组
echo "<h5>所有编程语言:</h5>";
foreach ($languages as $language) {
    echo $language . "<br>";
}

echo "<br><br>";

// 2. 关联数组示例

echo "<h4>2. 关联数组示例</h4>";

// 创建关联数组
$book = array(
    "title" => "PHP Programming",
    "author" => "John Smith",
    "publisher" => "Tech Books",
    "year" => 2020,
    "price" => 49.99
);

// 访问数组元素
echo "书名: " . $book["title"] . "<br>";
echo "作者: " . $book["author"] . "<br>";
echo "价格: $" . $book["price"] . "<br>";

// 修改数组元素
$book["price"] = 39.99;
echo "修改后的价格: $" . $book["price"] . "<br>";

// 添加新元素
$book["rating"] = 4.5;
echo "添加的评分: " . $book["rating"] . "<br>";

// 遍历关联数组
echo "<h5>图书信息:</h5>";
foreach ($book as $key => $value) {
    echo "$key: $value<br>";
}

echo "<br><br>";

// 3. 多维数组示例

echo "<h4>3. 多维数组示例</h4>";

// 创建二维数组
$employees = array(
    array("id" => 1, "name" => "John Doe", "department" => "HR", "salary" => 50000),
    array("id" => 2, "name" => "Jane Smith", "department" => "IT", "salary" => 60000),
    array("id" => 3, "name" => "Mike Johnson", "department" => "Finance", "salary" => 55000),
    array("id" => 4, "name" => "Lisa Davis", "department" => "Marketing", "salary" => 48000)
);

// 访问多维数组元素
echo "第一个员工姓名: " . $employees[0]["name"] . "<br>";
echo "第三个员工部门: " . $employees[2]["department"] . "<br>";

// 遍历二维数组
echo "<h5>员工信息表:</h5>";
echo "<table border='1' cellspacing='0' cellpadding='5'>";
echo "<tr><th>ID</th><th>姓名</th><th>部门</th><th>薪资</th></tr>";

foreach ($employees as $employee) {
    echo "<tr>";
    echo "<td>" . $employee["id"] . "</td>";
    echo "<td>" . $employee["name"] . "</td>";
    echo "<td>" . $employee["department"] . "</td>";
    echo "<td>$" . $employee["salary"] . "</td>";
    echo "</tr>";
}

echo "</table>";

echo "<br><br>";

// 4. 数组函数示例

echo "<h4>4. 数组函数示例</h4>";

// 数组排序
$numbers = array(5, 2, 8, 1, 9, 3);
echo "原始数组: " . implode(", ", $numbers) . "<br>";

sort($numbers);
echo "升序排序: " . implode(", ", $numbers) . "<br>";

rsort($numbers);
echo "降序排序: " . implode(", ", $numbers) . "<br>";

echo "<br>";

// 数组搜索
$fruits = array("apple", "banana", "orange", "grape", "mango");
$search_fruit = "orange";

if (in_array($search_fruit, $fruits)) {
    echo "$search_fruit 在数组中，索引为: " . array_search($search_fruit, $fruits) . "<br>";
} else {
    echo "$search_fruit 不在数组中";
}

echo "<br>";

// 数组过滤
$ages = array(18, 25, 30, 16, 14, 21, 40);
$adult_ages = array_filter($ages, function($age) {
    return $age >= 18;
});

echo "所有年龄: " . implode(", ", $ages) . "<br>";
echo "成年人年龄: " . implode(", ", $adult_ages) . "<br>";

echo "<br>";

// 数组合并
$array1 = array("a", "b", "c");
$array2 = array("d", "e", "f");
$merged_array = array_merge($array1, $array2);

echo "数组1: " . implode(", ", $array1) . "<br>";
echo "数组2: " . implode(", ", $array2) . "<br>";
echo "合并后的数组: " . implode(", ", $merged_array) . "<br>";

echo "<br>";

// 数组映射
$numbers = array(1, 2, 3, 4, 5);
$squared_numbers = array_map(function($number) {
    return $number * $number;
}, $numbers);

echo "原始数组: " . implode(", ", $numbers) . "<br>";
echo "平方后的数组: " . implode(", ", $squared_numbers) . "<br>";

echo "<br><br>";

// 5. 实际应用示例

echo "<h4>5. 实际应用示例</h4>";

// 示例1: 统计单词频率
function count_words($text) {
    // 转换为小写并替换非字母数字字符
    $text = strtolower($text);
    $text = preg_replace('/[^a-z0-9 ]/', '', $text);
    
    // 拆分为单词数组
    $words = explode(' ', $text);
    
    // 移除空元素
    $words = array_filter($words);
    
    // 统计频率
    $word_counts = array_count_values($words);
    
    // 按频率排序
    arsort($word_counts);
    
    return $word_counts;
}

// 测试单词频率统计
$text = "PHP is a popular general-purpose scripting language that is especially suited to web development. PHP is known for its simplicity and flexibility. PHP can be embedded into HTML.";
$word_counts = count_words($text);

// 显示结果
echo "<h5>单词频率统计:</h5>";
foreach ($word_counts as $word => $count) {
    echo "$word: $count 次<br>";
}

echo "<br>";

// 示例2: 计算数组的统计信息
function array_stats($array) {
    $stats = array();
    $stats["count"] = count($array);
    $stats["sum"] = array_sum($array);
    $stats["average"] = $stats["sum"] / $stats["count"];
    $stats["min"] = min($array);
    $stats["max"] = max($array);
    
    // 排序数组以计算中位数
    sort($array);
    $middle = floor($stats["count"] / 2);
    if ($stats["count"] % 2 == 0) {
        $stats["median"] = ($array[$middle-1] + $array[$middle]) / 2;
    } else {
        $stats["median"] = $array[$middle];
    }
    
    // 计算众数
    $values = array_count_values($array);
    $max_count = max($values);
    $modes = array_keys($values, $max_count);
    $stats["mode"] = $modes[0];
    
    return $stats;
}

// 测试数组统计信息
$scores = array(85, 92, 78, 90, 85, 95, 88, 90, 85, 92);
$stats = array_stats($scores);

// 显示结果
echo "<h5>数组统计信息:</h5>";
echo "数组元素: " . implode(", ", $scores) . "<br>";
echo "元素数量: " . $stats["count"] . "<br>";
echo "总和: " . $stats["sum"] . "<br>";
echo "平均值: " . $stats["average"] . "<br>";
echo "最小值: " . $stats["min"] . "<br>";
echo "最大值: " . $stats["max"] . "<br>";
echo "中位数: " . $stats["median"] . "<br>";
echo "众数: " . $stats["mode"] . "<br>";

echo "<br>";

// 示例3: 构建导航菜单
function build_nav_menu($items) {
    $menu = "<ul>\n";
    
    foreach ($items as $key => $item) {
        $menu .= "    <li>\n";
        
        if (is_array($item)) {
            // 有子菜单
            $menu .= "        <a href='#'>$key</a>\n";
            $menu .= "        <ul>\n";
            
            foreach ($item as $sub_key => $sub_item) {
                $menu .= "            <li><a href='{$sub_item}'>$sub_key</a></li>\n";
            }
            
            $menu .= "        </ul>\n";
        } else {
            // 无子菜单
            $menu .= "        <a href='{$item}'>$key</a>\n";
        }
        
        $menu .= "    </li>\n";
    }
    
    $menu .= "</ul>";
    
    return $menu;
}

// 测试导航菜单构建
$nav_items = array(
    "首页" => "index.html",
    "产品" => array(
        "智能手机" => "products/smartphones.html",
        "笔记本电脑" => "products/laptops.html",
        "平板电脑" => "products/tablets.html"
    ),
    "关于我们" => "about.html",
    "联系我们" => "contact.html"
);

// 显示导航菜单
echo "<h5>导航菜单示例:</h5>";
echo build_nav_menu($nav_items);

// 示例4: 处理表单数据
function process_form_data($form_data) {
    // 过滤和清理表单数据
    $clean_data = array();
    
    foreach ($form_data as $key => $value) {
        // 移除首尾空白字符
        $clean_value = trim($value);
        // 转义特殊字符
        $clean_value = htmlspecialchars($clean_value);
        // 存储清理后的数据
        $clean_data[$key] = $clean_value;
    }
    
    return $clean_data;
}

// 测试表单数据处理（模拟表单数据）
$form_data = array(
    "name" => " John Doe ",
    "email" => "john@example.com",
    "message" => "Hello, this is a test message! <script>alert('XSS')</script>"
);

$clean_data = process_form_data($form_data);

// 显示结果
echo "<br><h5>表单数据处理:</h5>";
echo "原始数据:<br>";
echo "<pre>". print_r($form_data, true) ."</pre><br>";
echo "清理后的数据:<br>";
echo "<pre>". print_r($clean_data, true) ."</pre><br>";

// 示例5: 构建查询字符串
function build_query_string($params) {
    $query_string = "";
    $first = true;
    
    foreach ($params as $key => $value) {
        if ($first) {
            $query_string .= "?";
            $first = false;
        } else {
            $query_string .= "&";
        }
        
        $query_string .= urlencode($key) . "=" . urlencode($value);
    }
    
    return $query_string;
}

// 测试查询字符串构建
$query_params = array(
    "page" => 1,
    "sort" => "name",
    "order" => "asc",
    "search" => "PHP教程"
);

$query_string = build_query_string($query_params);

echo "<h5>查询字符串示例:</h5>";
echo "查询参数: <pre>". print_r($query_params, true) ."</pre><br>";
echo "生成的查询字符串: " . $query_string . "<br><br>";
?>