Do you know some Java basics?

Which statement is true about Java?

• Java is a sequence-dependent programming language

• Java is a code dependent programming language

• Java is a platform-dependent programming language

• Java is a platform-independent programming language

Answer explanation

Java is called ‘Platform Independent Language’ as it primarily works on the principle of ‘compile once, run everywhere’.

Which of these cannot be used for a variable name in Java?

• Identifier & keywords

• Identifier

• Keywords

• None of the above

Answer explanation

Keywords are specially reserved words that can not be used for naming a user-defined variable.

For example: class, int, for, etc.

What is the extension of java code files?

• .txt

• .java

• .py

• .html

What will be the output of the following Java code?

• 16

• 24

• 32

• 48

Answer explanation

Operator ++ acts like a "plus 1" (increment), so g becomes 4 and when multiplied by 8 gives 32.

What is the extension of compiled java classes?

• .class

• .java

• .js

• .code

Which exception is thrown when java is out of memory?

• MemoryError

• OutOfMemoryError

• MemoryOutOfBoundsException

• MemoryFullException
  

Answer explanation

The Xms flag has no default value, and Xmx typically has a default value of 256MB. A common use for these flags is when you encounter a java.lang.OutOfMemoryError.

What will be the output of the following Java code?

• a

• b

• abc

• c

Answer explanation

String(chars) is a constructor of class string, it initializes string s with the values stored in character array chars, therefore s contains “abc”.

What will be the output of the following Java program?

• Quiz

• QuizziuQ

• ziuQQuiz

• ziuQ

Answer explanation

reverse() method reverses all characters. It returns the reversed object on which it was called.

Which one of the following is NOT an access modifier?

• Private

• Public

• Void

• Protected

Answer explanation

Public, private, protected and default are the access modifiers.

What is the numerical range of a char data type in Java?

• -128 to 127

• 0 to 256

• 0 to 32767

• 0 to 65535

Answer explanation

Char occupies 16-bit in memory, so it supports 2¹⁶ i:e from 0 to 65535.