How can I replace a specific key's value in an array in php?

Question

I have a an array that has 3 values. After the user pushes the submit button I want it to replace the the value of a key that I specify with another value.

If I have an array with the values (0 => A, 1 => B, 2 => C), and the function is run, the resulting array should be (0 => A, 1 => X, 2 => C), if for example the parameter for the function tells it to the replace the 2nd spot in the array with a new value.

How can I replace a specific key's value in an array in php?

Answer 1

If you know the key, you can do:

$array[$key] = $newVal;

If you don't, you can do:

$pos = array_search($valToReplace, $array);
if ($pos !== FALSE)
{
 $array[$pos] = $newVal;
}

Note that if $valToReplace is found in $array more than once, the first matching key is returned. More about array_search.

Answer 2

In case you want to have an inline solution you can use array_replace or array_replay_recrusive depending on which suits you best.

$replaced_arr = array_replace([
 'key' => 'old_value',
 0 => 'another_untouched_value'
 ],[
 'key' => 'new_value'
 ]);

It would be best if your array is key/value pair