Variable declaration and initialization - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a variable declaration in C?

A variable declaration in C tells the computer to create a space in memory to store a value of a specific type, but it does not assign a value yet.

beginner

What does variable initialization mean?

Variable initialization means giving a variable its first value at the time of declaration.

beginner

How do you declare and initialize an integer variable named 'age' with the value 25 in C?

int age = 25;

intermediate

What happens if you declare a variable but do not initialize it in C?

The variable contains a garbage value (random data) until you assign a value to it.

intermediate

Can you declare multiple variables of the same type in one line? Give an example.

Yes. For example: int x = 5, y = 10, z = 15;

Which of the following is a correct variable declaration and initialization in C?

A int = 10 number;

B number int = 10;

C int number = 10;

D int number : 10;

In C, the correct syntax is: type variable = value; so 'int number = 10;' is correct.

What value does an uninitialized local variable in C hold?

A One

B Zero

C Null

D Garbage (random) value

Local variables in C that are not initialized hold garbage values, which are unpredictable.

Which keyword is used to declare a variable in C?

A int, float, char (data types)

B let

C var

D declare

In C, variables are declared by specifying their data type like int, float, or char.

How do you declare three integer variables a, b, and c in one line?

A int a; int b; int c;

B int a, b, c;

C int a = b = c;

D int a b c;

You can declare multiple variables of the same type in one line separated by commas: int a, b, c;

What is the correct way to initialize a character variable named letter with 'A'?

A char letter = 'A';

B char letter = "A";

C char letter = A;

D char letter = (A);

Characters in C are enclosed in single quotes, so 'char letter = 'A';' is correct.

Explain the difference between variable declaration and initialization in C.

Think about what happens when you tell the computer about a variable versus giving it a value.

Write an example of declaring and initializing multiple variables of the same type in one line.

Use int type and assign values to variables a, b, and c.