Unable to change values in JSON array via str_replace - php

Question

I would like to change values in an array. Here is my starting array:
Array
(
[0] => Array
(
[name] => aaa
)
[1] => Array
(
[name] => bbb
)
[2] => Array
(
[name] => ccc
)
)
I declare a searchterm (eg. "aaa") and a new name for it (eg. "test"). And than I do a str_replace to actually change it.
Unfortunately nothing changes nor do I get an error message. Can you please help and tell me where my error is please?
for ($i=0; $i < count($json) ; $i++) {
$search = $old_name;
$replace = $new_name;
str_replace($search, $replace, $json[$i]['name']);
print_r($json);
}

Answer 1

As the documentation says, this function doesn't update the array
This function returns a string or an array with the replaced values.
you need to update it with the returned value:
for ($i=0; $i < count($json) ; $i++) {
$search = $old_name;
$replace = $new_name;
$json[$i]['name'] = str_replace($search, $replace, $json[$i]['name']);
print_r($json);
}

Answer 2

str_replace returns a string. I think you are trying to use it as though it alters a parameter that was passed by reference. Instead you should assign the returned value to the array at the correct index.
for ($i=0; $i < count($json) ; $i++) {
$search = $old_name;
$replace = $new_name;
$json[$i]['name'] = str_replace($search, $replace, $json[$i]['name']);
print_r($json);
}

Answer 3

If you want to replace/change more than one name, I suggest you to use the below code.
// define an array with keys as new name and value as old name ( name to be replaced).
$change_name_array= array('test'=>'aaa','another_test'=>'bbb');
// loop the array
for ($i=0; $i < count($json) ; $i++) {
// check if the name is in defined array
if(in_array($json[$i]['name'],$change_name_array)){
// get the key and replace it.
$json[$i]['name'] = array_search($json[$i]['name'], $change_name_array);
}
}
Out put: here aaa id replaced with test and bbb is replaced with another_test
Array
(
[0] => Array
(
[name] => test
)
[1] => Array
(
[name] => another_test
)
[2] => Array
(
[name] => ccc
)
)