Accessing structure members - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a structure in C?

A structure in C is a user-defined data type that groups different variables under one name, allowing you to store related data together.

beginner

How do you access a member of a structure variable in C?

You use the dot operator (.) to access a member of a structure variable. For example, if person is a structure variable and age is a member, you write person.age.

beginner

How do you access a member of a structure through a pointer in C?

You use the arrow operator (->) to access a member of a structure through a pointer. For example, if p is a pointer to a structure and name is a member, you write p->name.

intermediate

What is the difference between the dot (.) and arrow (->) operators in C structures?

The dot operator (.) is used to access members of a structure variable directly, while the arrow operator (->) is used to access members through a pointer to a structure.

beginner

Given struct Point { int x; int y; } p;, how do you set the x coordinate to 10?

You write p.x = 10; to set the x coordinate of the structure variable p to 10.

Which operator is used to access a member of a structure variable in C?

A . (dot)

B -> (arrow)

C * (asterisk)

D & (ampersand)

The dot operator (.) is used to access members of a structure variable directly.

How do you access a structure member through a pointer in C?

A Using the asterisk (*)

B Using the dot operator (.)

C Using the arrow operator (->)

D Using the ampersand (&)

The arrow operator (->) is used to access members through a pointer to a structure.

Given struct Person { int age; } *ptr;, how do you access the age member?

A ptr.age

B &ptr.age

C *ptr.age

D ptr->age

You use ptr->age to access the age member through the pointer.

What will happen if you try to use the dot operator on a pointer to a structure?

A It works fine

B It causes a compilation error

C It accesses the member correctly

D It dereferences the pointer automatically

Using the dot operator on a pointer to a structure causes a compilation error because the pointer must be dereferenced first or use the arrow operator.

If p is a structure variable, which of these is correct to assign 5 to member val?

A p.val = 5;

B *p.val = 5;

C p->val = 5;

D &p.val = 5;

You use the dot operator to assign a value to a member of a structure variable.

Explain how to access members of a structure variable and a pointer to a structure in C.

Think about how you access properties of an object directly versus through a pointer.

Describe the difference between the dot (.) and arrow (->) operators when working with structures in C.

Consider what happens when you have a pointer versus a normal variable.