I have an array with a key and 3 values (day, start_time, end_time). I want to keep adding certain entries into this array while making sure each entry is unique. That means that every time I try to add an item into the array, I want to make sure it does not already exist in it. If it does exist, I want to be able to find the key that indicates that entry.
For example, this is the pre-existing array:
$array [0][0] = Monday
$array [0][1] = 2
$array [0][2] = 4
$array [1][0] = Tuesday
$array [1][1] = 3
$array [1][2] = 5
If I try to insert (Wednesday, 3, 5), then it should make the entry in the index 2.
If I try to insert (Monday, 2, 4), I need to be able to know that it is already in there and is indexed by 0.
How do I go about doing this?