uni/year2/semester1/logseq-stuff/pages/Sorting & Testing.md

• #CT2106 - Object-Oriented Programming
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• Natural Ordering

  • When deciding on whether one object is greater than or less than another, we refer to the natural ordering of the object's class.
  • Natural ordering is the ordering imposed on an object when its class implements the Comparable interface.

    • public interface Comparable<T>
      

    • This interface imposes a total ordering on the objects of each class that implements it.
    • The class's compareTo() method is referred to as its natural comparison method.
    • Lists (and arrays) that implement this interface can be sorted automatically by Collections.sort.
    • Objects that implement this interface can be used as keys in a sorted map or as elements in a sorted set, without the need to specify a comparator.
    • The <T> in Comparable<T> means that we can specify in advance the types of the object that should be compared.
    • It returns a negative integer, zero, or a positive integer depending on whether the object is less than, equal to, or greater than the specified object.

• assert

  • Use assert to declare that a statement must be true.
    • If it is not true, your program will throw an AssertionError Exception.
    • You can use the assert statement as a quick way to test for expected output.

    • assert(2==2);