How to find and replace specific value in multiple array - php

Question

I want to find flag key from array and replace new value. for example if i found flag values == 2 then i'll put new value instead of old.
Following is my array.
Array
(
[0] => Array
(
[id] => 863
[flag] => 1
[qty] => 2
[size] => 8
[fly_name] => Bead Headed Prince Nymphs size 18
)
[1] => Array
(
[id] => 861
[flag] => 1
[qty] => 2
[size] => 8
[fly_name] => Bead Headed Prince Nymphs size 14
)
[2] => Array
(
[id] => 671
[flag] => 1
[qty] => 4
[size] => 8
[fly_name] => Royal Wulff size 12
)
[3] => Array
(
[id] => 661
[flag] => 1
[qty] => 2
[size] => 3
[fly_name] => Hare's Ear Tan size 16
)
)
I want to find if flag key == 2 then replace new value of flag key , i have tried following way but not work.
if(in_array(2, $fliesUserColumn)) { // search value in the array
foreach($fliesUserColumn as $key => $val)
{
if ($val == '2') $fliesUserColumn[$key] = 'search4';
}
}else{
echo "not";
}
echo "<pre>";
print_r ($flyOfStores);
echo "</pre>";
die;
And out put like with new values in array
Array
(
[0] => Array
(
[id] => 863
[flag] => newvalue
[qty] => 2
[size] => 8
[fly_name] => Bead Headed Prince Nymphs size 18
)
[1] => Array
(
[id] => 861
[flag] => newvalue
[qty] => 2
[size] => 8
[fly_name] => Bead Headed Prince Nymphs size 14
)
...
)

Answer 1

Try below example
foreach ($fliesUserColumn as $key => $val) {
if ($fliesUserColumn[$key]['flag'] == '2') {
$fliesUserColumn[$key]['flag'] = 'Newvalue';
}
}

Answer 2

Try this
foreach ($fliesUserColumn as $key => $val) {
if ($fliesUserColumn[$key]['flag'] == '2') {
$fliesUserColumn[$key] = 'search4';
} else {
echo "not";
}
}