M_Sander:
I do have a small project, there is two arrays. Array no#1 holding ascending sorted values. This table is the input data
Array no#2 is the output data. It contains other values that are not linear but corresponds to Array no#1 index position.
As mentioned by Holmes4, that is almost a textbook description of a lookup table. I do not know if there is an accepted name for that design pattern, but the hash table is very similar. That's going to be the fastest search, but it does require all possible inputs to be available, and have some sort of mathematical relationship to the array indices, so you can calculate array indices directly from the input.
A hash table uses a hash function to compute an index into an array of buckets or slots, from which the correct value can be found.