Software testing study notes: equivalence class division method

Effectiveness division

Effective equivalence class: meets the demand
Invalid equivalence class: does not meet the demand

Equivalence operation steps

Design a new test case to cover as many valid equivalence classes as possible that have not been covered, and
repeat this process until all valid equivalence classes are covered by the test cases ;

Design a new test case to cover only one invalid equivalence class,
repeat this process until all invalid equivalence classes are covered by the test case

Boundary value

To design test cases using boundary value analysis methods, first determine the boundary conditions .
Usually the boundary of the input and output equivalence classes is the boundary case that should be tested.
The value that is exactly equal to, just greater than or just less than the boundary should be selected as the test data ,
rather than the typical value or any value in the equivalence class as the test data

10<=x<=20
Test value: 9,10,20,21
on point 10,20 and
off point 9,21