Java Operators and Data Types Quiz

Which operator is used for logical "AND" operation?

• &&

• &

• ||

• |

Answer explanation

The logical "AND" operation is represented by the operator "&&". It evaluates to true only if both operands are true, making it the correct choice for this operation.

What is the output of the expression true || false?

• true

• false

• null

• 0

Answer explanation

The expression true || false uses the logical OR operator. It evaluates to true if at least one operand is true. Since the first operand is true, the entire expression results in true.

Which of the following is not a primitive data type in Java?

• byte

• String

• double

• short

Answer explanation

In Java, primitive data types include byte, short, and double. String, however, is a reference type, not a primitive type, making it the correct answer to the question.

Which of the following data types can store a floating-point number?

• int

• byte

• double

• char

Answer explanation

The 'double' data type is designed to store floating-point numbers, allowing for decimal values. In contrast, 'int', 'byte', and 'char' are used for whole numbers and characters, respectively, and cannot represent floating-point values.

Which data type can store a single character?

• String

• byte

• char

• int

Answer explanation

The 'char' data type is specifically designed to store a single character, making it the correct choice. In contrast, 'String' can hold multiple characters, while 'byte' and 'int' are used for numerical data.

Which loop construct in Java is best suited when the number of iterations is known?

• for loop

• while loop

• do-while loop

• break statement

Answer explanation

The 'for loop' is ideal when the number of iterations is known, as it allows you to initialize a counter, set a condition, and increment the counter in a single line. This makes it concise and easy to manage.

Which loop construct in Java is best suited when the number of iterations is unknown?

• for loop

• while loop

• do-while loop

• none

Answer explanation

The while loop is best suited for situations where the number of iterations is unknown, as it continues to execute as long as a specified condition remains true, allowing for dynamic iteration based on runtime conditions.

What is an infinite loop?

• A loop that executes only once

• A loop that never terminates naturally

• A loop that contains an unreachable code block

• A loop that uses the continue statement

Answer explanation

An infinite loop is defined as a loop that never terminates naturally, meaning it continues to execute indefinitely without reaching an exit condition. This distinguishes it from other types of loops that may terminate.

Which statement is used to exit a loop prematurely?

• return statement

• continue statement

• break statement

• exit statement

Answer explanation

The 'break statement' is used to exit a loop prematurely, terminating the loop's execution. In contrast, 'continue' skips to the next iteration, while 'return' exits a function, and 'exit' is not a standard loop control statement.

Which loop construct is best suited for iterating over an array or a collection?

• for loop

• while loop

• do-while loop

• continue statement

Answer explanation

The for loop is best suited for iterating over an array or collection because it provides a clear structure for initialization, condition checking, and iteration, making it easy to traverse elements efficiently.