PHP foreach with Nested Array
Question: How to access a specific nested array using a foreach loop in PHP?
Consider the following nested array:
<code class="php">array(
[0] => array(
[0] => one
[1] => array(
[0] => 1
[1] => 2
[2] => 3
)
)
[1] => array(
[0] => two
[1] => array(
[0] => 4
[1] => 5
[2] => 6
)
)
[2] => array(
[0] => three
[1] => array(
[0] => 7
[1] => 8
[2] => 9
)
)
)
);</code>The goal is to iterate through the values of the nested array at key 1, without using a variable comparison.
Answer: There are two approaches to achieve this:
1. Nested Loops (Fixed Depth):
This method is suitable if the depth of the nested arrays is known in advance.
<code class="php">foreach ($tmpArray as $innerArray) {
if (is_array($innerArray)) {
foreach ($innerArray as $value) {
echo $value;
}
} else {
echo $innerArray;
}
}</code>2. Recursive Function (Unknown Depth):
This approach is used when the depth of the nested arrays is unknown. It involves a recursive function that traverses the array:
<code class="php">function displayArrayRecursively($arr, $indent='') {
if ($arr) {
foreach ($arr as $value) {
if (is_array($value)) {
displayArrayRecursively($value, $indent . '--');
} else {
echo "$indent $value \n";
}
}
}
}
$tmpArray = array(
array("one", array(1, 2, 3)),
array("two", array(4, 5, 6)),
array("three", array(7, 8, 9))
);
displayArrayRecursively($tmpArray);</code>Specific Case:
To access only the nested array with values for the third level (key 2), use the following code:
<code class="php">foreach ($tmpArray as $inner) {
if (is_array($inner)) {
foreach ($inner[1] as $value) {
echo "$value \n";
}
}
}</code>以上是如何在 PHP 中使用 foreach 存取特定索引處的巢狀陣列？的詳細內容。更多資訊請關注PHP中文網其他相關文章！
