Replacing array value in foreach loop
What am I doing wrong here? It's so simple and I'm overlooking something. I'm trying to replace the value of an array key within a foreach loop:
$arr = array();
$arr['firstimg'] = '123';
$arr['secondimg'] = '456';
$arr['thirdimg'] = '789';
foreach ($arr as $key => $value) {
if ($key == 'secondimg') {
$value = '000';
}
}
print_r($arr);
The array is staying the same.
The variable $value is scoped to the loop. You need to update the value of $arr[$key] .
Alternatively you can declare the loop as follows:
foreach ($arr as $key => &$value) {
This makes $value a reference to the original array value (rather than a copy).
应该 ：
foreach ($arr as $key => $value) {
if ($key == 'secondimg') {
$arr['secondimg'] = '000';
}
}
pass by refrence,
$arr = array();
$arr['firstimg'] = '123';
$arr['secondimg'] = '456';
$arr['thirdimg'] = '789';
foreach ($arr as $key => $value) {
if ($key == 'secondimg') {
$value = '000';
}
}
print_r($arr);
to
$arr = array();
$arr['firstimg'] = '123';
$arr['secondimg'] = '456';
$arr['thirdimg'] = '789';
foreach ($arr as $key => &$value) {
if ($key == 'secondimg') {
$value = '000';
}
}
print_r($arr);
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