Selection
Selection is a very important concept in programming. It is one of the three basic logic structures. It is often called a decision structure as it "decides" what code to run.
In selection a question is asked, and depending on the answer, the program takes one of two courses of action.
This structure is sometimes referred to as if then else:
- If Condition A is True
- Then do this Action (X)
- Else (otherwise) do this Action (Y) instead.
So in the Scratch example, if the answer is 9 then that condition is true and it will carry out the Then action and say "Correct." (Note - neither Scratch or Python use the word then in these statements - but it is implied)
In the Python example the condition is false because a does not equal b, (10 is not equal to 20) so the Else action will be carried out.. it will print "no"