You must evaluate if the sequence of activities (or instructions) will result in the required outcomes. This evaluation can be logical, arithmetic, or both.
A common scenario is evaluating the order of conditionals. You must become very good at tracing conditional expressions.
You should remember your order of operations:
In mathematics and computer programming, the order of operations (or operator precedence) is a collection of rules that reflect conventions about which procedures to perform first in order to evaluate a given mathematical expression. The mathematical order of operation is: PEMDAS (Parentheses, Exponents, Multiplication, Division, Addition, Subtraction).
How to evaluate a process
Use a step-by-step process and trace the value of a variable or value. Ask yourself, at each step in the process, what is the current value or state of a variable. Let's look at some examples.
Imagine you are writing a simple computer program which must output the winner of a game. A winner is determined by the highest numerical score (int). The input is two scores. The output must be only one of the scores below:
- The first score is the winner
- The second score is the winner
- There is a tie
def whoIsTheWinner(score1, score2): if score1 > score2: winner = "The first score is the winner" elif score2 > score1: winner = "The second score is the winner" else: winner = "There is a tie" return winner
If we were to evaluate this process, we would stop at each line of execution the value of each variable (score1 and score2). We would then ask ourselves:
- If score1 is higher than score2, would the program output score1 is the winner?
- If score2 is higher than score1, would the program output score2 is the winner?
- If both scores are the same, would the program output there is a tie?
Other Questions to code:
- If John is a bachelor, then he is male. John is male. Therefore, John is a bachelor.
- If today is Monday, then I will attend cooking class today.
- Either the current pope is married or he is a divorcé.
- Evaluate whether the order in which activities are undertaken will result in the required outcome.