Assignment and compound assignment in C Sharp (C#) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the assignment operator = in C#?

The assignment operator = is used to store a value into a variable. It takes the value on the right and puts it into the variable on the left.

beginner

What does the compound assignment operator += do?

The += operator adds the value on the right to the variable on the left and then stores the result back into that variable. It's a shortcut for variable = variable + value.

beginner

Explain the difference between = and += operators.

= assigns a new value to a variable, replacing the old one. += adds a value to the current value of the variable and updates it with the sum.

beginner

Given int x = 5; what is the value of x after x *= 3;?

The value of x becomes 15 because x *= 3 multiplies x by 3 and assigns the result back to x.

beginner

Can compound assignment operators be used with strings in C#? For example, str += "hello";

Yes, the += operator can be used to append strings. It adds the right string to the end of the left string and stores the result.

What does the statement count -= 2; do?

A Subtracts 2 from count and updates count

B Assigns 2 to count

C Adds 2 to count

D Multiplies count by 2

The -= operator subtracts the value on the right from the variable on the left and updates it.

Which operator is equivalent to number = number / 4;?

A number += 4;

B number /= 4;

C number *= 4;

D number -= 4;

The /= operator divides the variable by the value and assigns the result back.

What is the value of total after total = 10; total += 5;?

A 15

B 10

C 5

D 50

The += operator adds 5 to 10, so total becomes 15.

Which of these is NOT a compound assignment operator in C#?

A +=

B -=

C *=

D ==

== is a comparison operator, not an assignment operator.

If str = "Hi";, what does str += " there"; do?

A Replaces str with " there"

B Deletes str

C Appends " there" to str

D Throws an error

The += operator appends the string on the right to the existing string.

Explain how compound assignment operators simplify code compared to using regular assignment.

Think about how you can do math and assignment in one step.

List at least three compound assignment operators in C# and describe what each does.

Remember operators that combine math with assignment.