boundary value analysis testcases for prime number code example

Example 1: equivalence class partitioning

Equivalence Partitioning is type of black box
testing technique which can be applied to
all levels of software testing like unit,
integration, system, etc. In this technique,
input data units are divided into equivalent
partitions that can be used to derive test
cases which reduces time required for testing 
because of small number of test cases.

It divides the input data of software
into different equivalence data classes.
You can apply this technique, 
where there is a range in the input field.

Example 2: boundary value analysis

The basic idea in normal boundary 
value testing is to select input
variable values at their:
Minimum
Just above the minimum
A nominal value
Just below the maximum
Maximum