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.