如何在PHP中基于键删除数组元素
要基于PHP中的键删除数组元素，代码如下-
示例
<?php
$arr = array( " John ", "Jacob ", " Tom ", " Tim ");
echo "具有前导和尾随空格的数组...\n";
foreach( $arr as $value ) {
echo "Value = $value \n";
}
echo "\n逗号分隔列表...\n";
print_r(implode(', ', $arr));
$result = array_map('trim', $arr);
echo "\n更新后的数组...\n";
foreach( $result as $value ) {
echo "Value = $value \n";
}
unset($result[1]);
echo "\n更新后的数组...\n";
foreach( $result as $value ) {
echo "Value = $value \n";
}
?>输出结果
具有前导和尾随空格的数组... Value = John Value = Jacob Value = Tom Value = Tim 逗号分隔列表... John , Jacob , Tom , Tim 更新后的数组... Value = John Value = Jacob Value = Tom Value = Tim 更新后的数组... Value = John Value = Tom Value = Tim
示例
现在让我们来看另一个示例-
<?php
$marks = array(
"kevin" => array (
"physics" => 95,
"maths" => 90,
),
"ryan" => array (
"physics" => 92,
"maths" => 97,
),
);
echo "kevin 的物理成绩 : " ;
echo $marks['kevin']['physics'] . "\n";
echo "ryan 的数学成绩 : ";
echo $marks['ryan']['maths'] . "\n";
unset($marks["ryan"]);
echo "ryan 的数学成绩 : ";
echo $marks['ryan']['maths'] . "\n";
?>输出结果
这将产生以下输出。现在，由于我们删除了该元素并尝试访问该元素，因此将看到一个错误-
kevin 的物理成绩 : 95 ryan 的数学成绩 : 97 ryan 的数学成绩 : PHP Notice: Undefined index: ryan in /home/cg/root/6985034/main.php on line 25