Question

Which of the following are not valid assignment statements?. A) total $=9$ B) $72=$ amount: C) yourAge $=$ myAge:

Short answer

A) total = 9 B) 72 = amount C) yourage = myAge Answer: B) 72 = amount

Step-by-step solution

Statement A: total = 9

The value 9 is on the right-hand side and is being assigned to the variable 'total' on the left-hand side. This is a valid assignment statement.

Statement B: 72 = amount

The value 72 is on the left-hand side and is supposed to be assigned to the variable 'amount' on the right-hand side. However, assignment statements should have the variable on the left side and the value on the right side. Thus, this is not a valid assignment statement.

Statement C: yourage = myAge

The variable 'myAge' is on the right-hand side and is being assigned to the variable 'yourage' on the left-hand side. Since both sides have variables and the assignment order is correct, this is a valid assignment statement. In conclusion, the statement B is not a valid assignment statement.

Key concepts

C++ Programming

C++ programming is a powerful language often used for system/software development and game programming. It provides a structured approach to coding, which helps in creating complex applications efficiently. Understanding the basics of C++ is essential for writing code that is both functional and efficient.

In the context of our exercise, knowing that C++ code follows a specific syntax is crucial. The syntax rules include how to write valid assignment statements, declaring variables, and understanding data types, among others. For students learning to program in C++, grasping these syntactic rules helps prevent common errors that can lead to faulty programs.

Variable Assignment

Variable assignment in C++ is the process of storing a value in a variable. The assignment operator, which is the equal sign '=', is used for this purpose. The typical syntax for an assignment statement is: variable_name = value;

Following this syntax is critical, as it tells the compiler what value to store and where to store it. For example, in our exercise, total = 9; correctly assigns the integer value 9 to the variable named 'total'. Remember, the variable must always come on the left side of the assignment operator.

It's also worth noting that the variable must be declared before it can be assigned a value, and the type of data on the right side of the assignment must match the variable's declared type. These are key points that students should remember for error-free variable assignment in their C++ programs.

Syntax Errors

Syntax errors occur when code violates the grammatical rules of the programming language. In C++, as with other programming languages, such mistakes can cause the program to fail to compile, meaning it will not run at all. Correct syntax is imperative to create programs that execute as intended.

Common syntax errors include misspelling keywords, forgetting semicolons at the end of statements, or in the case of our exercise, writing an assignment statement backwards, as seen in 72 = amount; Here, because the constant '72' cannot be assigned a value, the proper statement should be amount = 72; Another aspect is the unnecessary colon observed in yourage = myAge: While this might not lead to a compilation error in some compilers, it is considered bad practice and could cause issues in different contexts.

To prevent syntax errors, students should double-check their code for typing mistakes, ensure all statements are ended properly, and follow the standard language conventions for C++ programming.