Q19
What is the result of the expression: 3 * (4 + 2) in C++?
A.
18
AnswerB.
20
C.
12
D.
Compiler error
Answer: Option A
Solution
Answer: Option A
Solution:
Let's break down this C++ expression step by step, just like you would in regular math!The expression is: 3 * (4 + 2)
In C++ (and most programming languages), we follow a set of rules called operator precedence. This means some operations are performed before others. It's similar to the PEMDAS (Parentheses, Exponents, Multiplication/Division, Addition/Subtraction) or BODMAS rule you might know from mathematics.
The most important rule here is: Parentheses ( ) always come first! Any calculation inside parentheses is done before anything outside them.
1. First, evaluate the expression inside the parentheses:
We have (4 + 2).
4 + 2 = 6
2. Now, substitute this result back into the original expression:
The expression now becomes: 3 * 6
3. Finally, perform the multiplication:
3 * 6 = 18
So, the result of the expression 3 * (4 + 2) in C++ is 18.
Therefore, Option A: 18 is the correct answer.
Why not other options?
* Options B and C are incorrect because they do not follow the correct order of operations. If you did 3 * 4 first (12), then added 2, you'd get 14, which is not an option and still incorrect. The parentheses *must* be solved first.
* Option D: Compiler error is incorrect because this is a perfectly valid and well-formed C++ expression. The compiler understands the parentheses and the operators (* and +) and will correctly calculate the result.