Increment and decrement operators - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the increment operator (++) do in C?

It increases the value of a variable by 1.

intermediate

What is the difference between prefix (++x) and postfix (x++) increment?

Prefix increments the value before using it, postfix uses the value first then increments it.

beginner

What does the decrement operator (--) do in C?

It decreases the value of a variable by 1.

intermediate

How does the postfix decrement (x--) behave in an expression?

It uses the current value of x in the expression, then decreases x by 1.

advanced

Can increment and decrement operators be used with non-integer types in C?

Yes, they can be used with types like char and pointers, increasing or decreasing their value accordingly.

What will be the value of x after this code? <br> int x = 5; <br> x++;

A 6

B 5

C 4

D Error

The x++ increases x by 1, so x becomes 6.

What is the output of this code? <br> int x = 3; <br> printf("%d", ++x);

A Error

B 3

C Undefined

D 4

++x increments x first, so x becomes 4, then prints 4.

Which operator decreases a variable's value by 1?

A ++

B --

C +=

D -=

-- is the decrement operator that subtracts 1 from the variable.

What is the difference between x++ and ++x in expressions?

A x++ increments after use, ++x increments before use

B x++ increments before use, ++x increments after use

C No difference

D Both cause errors

x++ uses the value first then increments; ++x increments first then uses the value.

Can you use increment operators on pointers in C?

A Yes, but only on char pointers

B No, only on integers

C Yes, it moves the pointer to the next memory location

D Only on arrays

Incrementing a pointer moves it to the next element in memory according to its type size.

Explain how prefix and postfix increment operators work differently in C.

Think about when the variable's value changes relative to its use.

Describe how decrement operators can be used with pointers and what effect they have.

Consider how memory addresses change when you decrement a pointer.