Ensures the truth of an expression involving one or more parameters to the calling method. Ensures the truth of an expression involving one or more parameters to the calling method. ... Ensures that an object reference passed as a parameter to the calling method is not null.

What is a precondition in Java?

The precondition is what the method expects in order to do its job properly. A postcondition is a condition that is true after running the method. It is what the method promises to do. Postconditions describe the outcome of running the method, for example what is being returned or the changes to the instance variables.

What is precondition check?

Introduction : The Preconditions Class provides a list of static methods for checking that a method or a constructor is invoked with valid parameter values. If a precondition fails, a tailored exception is thrown. These methods generally accept a boolean expression which is expected to be true.