Returns 1 if the search term exists in string or array and 0 if it doesn’t.
An empty string is never found in a string. This differs from Python where empty strings are found at the start of the string.
The stop and end values constrain the search to those
ranges. The end index is not included in the search, so should be
len(array) to search the entire array. The start index is included.
Negative indices are not supported for the find range.