如何使用foreach列出键值关联数组 - How to list key-value associative array using foreach

How to list key-value associative array using foreach

假设我们有一个数组:

$aa = array('student1'=>array(1,2,3),'student2'=>array(3,2,4),'student3'=>array(4,3,5));

我想有一个像下面这样的HTML输出:

<ul>
    <li>student1
        <ul>
            <li>1</li>
            <li>1</li>
            <li>1</li>
        </ul>
    </li>
    <li>student2
        <ul>
            <li>3</li>
            <li>2</li>
            <li>4</li>
        </ul>
    </li>
    <li>student3
        <ul>
            <li>4</li>
            <li>3</li>
            <li>5</li>
        </ul>
    </li>
</ul>

但我所能做的就是

<ul>
    <li>
        <ul>
            <li>1</li>
            <li>1</li>
            <li>1</li>
        </ul>
    </li>
    <li> 
        <ul>
            <li>3</li>
            <li>2</li>
            <li>4</li>
        </ul>
    </li>
    <li> 
        <ul>
            <li>4</li>
            <li>3</li>
            <li>5</li>
        </ul>
    </li>
</ul>

换句话说，我不能为每个内部数组打印键。怎么做呢?

我写了这样的代码:

echo '<ul>';
foreach($aa as $a)
{
    echo '<li>' . /*Here it should be written the current student name*/ '<ul>';
    foreach($a as $b)
    {
        echo '<li>' . $b . '</li>';
    }
    echo '</ul></li>';
}
echo '</ul>';

<ul>
<?php
  foreach ($aa as $name => $values) {
    echo "<li>$name'n";
    echo "<ul>'n";
    foreach ($values as $value) {
      echo "<li>$value</li>'n";
    }
    echo "</ul>'n";
    echo "</li>'n";
  }
?>
</ul>

像这样打印数组:

echo "<pre>";
print_r($array);
echo "</pre>";

这样可以看到数组的内部结构。

那么你可以这样列出:

$a = array(
    "one" => 1,
    "two" => 2,
    "three" => 3,
    "seventeen" => 17
);
foreach ($a as $k => $v) {
    echo "'$a[$k] => $v.'n";
}