Understanding the simultaneous traversal pattern

We traverse an array to search for and perform operations on some data items. However, there are cases where we may need to operate on data items from two arrays of different sizes at once. This requires traversing both arrays at the same time, and the decision to move to the next item in any of those may depend on the outcome of some function. We may move ahead only in one array or in both of them. The simultaneous traversal technique can be used to iterate in both arrays simultaneously in a single pass.