APCSA 1.2 — Variables & Data Types

1) What is a variable in Java?

A. A labeled box in memory that stores data B. A mathematical equation C. A type of operator D. A package import E. A runtime exception

2) What are the three key parts of a variable?

A. Name, type, and value B. Name, method, and loop C. Class, package, and import D. Input, output, and result E. Declaration, scope, and object

3) Which of the following declares a variable correctly?

A. int age; B. age int; C. integer age; D. var age; E. int: age;

4) What is the process of giving a variable its first value called?

A. Initialization B. Declaration C. Casting D. Compilation E. Iteration

5) Which line both declares and initializes a variable?

A. int age = 17; B. age = int 17; C. declare age = 17; D. var age == 17; E. new int age(17);

6) Which data type holds whole numbers?

A. int B. double C. boolean D. char E. String

7) Which Java type is used for decimal numbers?

A. double B. int C. boolean D. char E. String

8) Which primitive type can store logical values like true or false?

A. boolean B. char C. int D. double E. String

9) Which primitive data type represents a single Unicode character?

A. char B. String C. boolean D. int E. float

10) Which of the following is NOT a primitive type in Java?

A. String B. int C. double D. boolean E. char

11) Which type is considered a reference type in Java?

A. String B. int C. double D. boolean E. char

12) Which statement correctly creates a String variable?

A. String name = "Shrek"; B. char name = 'Shrek'; C. string name = Shrek; D. String name = Shrek; E. new String = name;

13) What does name.length() return for a String?

A. The number of characters B. The number of words C. The data type of the string D. The first character E. The number of uppercase letters

14) What will name.toUpperCase() do?

A. Convert all characters to uppercase B. Count capital letters C. Return a boolean value D. Replace spaces with underscores E. Reverse the string

15) Why are Strings not considered primitive types?

A. Because they are objects and have methods B. Because they store only numbers C. Because they cannot change values D. Because they are declared using single quotes E. Because they are not stored in memory

16) Which assignment is valid (widening conversion)?

A. double y = x; where x is an int B. int x = y; where y is a double C. boolean flag = 1; D. char c = "A"; E. String s = 'A';

17) Which assignment causes a narrowing error without casting?

A. int x = y; where y is a double B. double y = x; where x is an int C. char c = 'A'; D. boolean flag = false; E. String s = "Hello";

18) What symbol is used for String concatenation?

A. + B. * C. & D. % E. #

19) What is the output of System.out.println("Score: " + 100);?

A. Score: 100 B. Score 100 C. Score: +100 D. 100 Score: E. Score 100:

20) Which example shows explicit casting?

A. int dollars = (int) price; B. double y = 7; C. int x = 10; D. boolean flag = true; E. char c = 'C';

21) What happens during a cast from double to int?

A. The decimal part is dropped B. The number is rounded up C. The value doubles D. The number becomes a String E. A runtime error occurs

22) What does it mean that a variable must be declared before use?

A. It must have a type defined first B. It must be printed before use C. It must be assigned 0 D. It must be cast E. It must be a String

23) Which statement is true about primitive vs reference types?

A. Primitives store raw values; references store objects B. Both store objects C. Primitives store text; references store numbers D. Primitives cannot be assigned E. References cannot hold data

24) What is the correct way to change a variable’s value?

A. Assign it a new value using = B. Redeclare it with a new type C. Use a cast automatically D. Call System.change() E. Use String.replace()

25) Which of the following best summarizes this unit?

A. Variables store data with names and types that determine their behavior B. Java cannot handle text values C. Strings are primitive values like integers D. All types can change automatically E. Boolean values store numbers