Java Programming - Level 1

Explanation: void method does not return any value.

Explanation: main() method must be specified public as it called by Java run time system, outside of the program. If no access specifier is used then by default member is public within its own package & cannot be accessed by Java run time system.

Explanation: None

The keyword "extends" must be used to inherit a class. Inheritance is a mechanism in object-oriented programming that allows a class to inherit the properties and methods of another class. By using the "extends" keyword, a subclass can inherit the attributes and behaviors of a superclass, enabling code reuse and promoting a hierarchical structure in the program.

The keyword "interface" is used to define interfaces in Java. In Java, an interface is a collection of abstract methods that can be implemented by a class. It defines a contract that a class must adhere to if it wants to implement that interface. The other options "Interface", "intf", and "Intf" are not valid keywords in Java for defining interfaces.

The keyword "package" is used to define packages in Java. Packages are used to organize classes and interfaces into groups, making it easier to manage and maintain large codebases. By using the "package" keyword followed by the package name, developers can create a hierarchical structure for their code. This allows for better organization, reusability, and encapsulation of code.

Explanation: Object class is a superclass of every class in java

The correct answer is "Object" because in Java, the Object class is the root class for all other classes. It is at the top of the class hierarchy and serves as the superclass for all other classes. Every class in Java directly or indirectly extends the Object class, which provides basic functionalities and methods that are inherited by all other classes.

Serialization is the process of writing the state of an object to a byte stream. This is used when you want to save the state of your program to the persistent storage area.

The keyword "super" can be used in a subclass to call the constructor of the superclass. It is used to invoke the superclass constructor and initialize the inherited members of the subclass. This allows the subclass to inherit and utilize the functionality of the superclass while also adding its own unique features.

Explanation: Order of precedence is (highest to lowest) a -> b -> c -> d.

The method "equals()" is used to compare two String objects for their equality. This method checks if the content of the two strings is the same, regardless of their memory location. It returns a boolean value, true if the strings are equal, and false if they are not.

Operator new allocates a block of memory specified by the size of array, and gives the reference of memory allocated to the array variable.

Explanation: StringBuffer represents growable and writeable character sequence.

Explanation: InputStream & OutputStream are designed for byte stream. Reader and writer are designed for character stream.

Explanation: Two or more methods can have the same name as long as their parameters declaration is different, the methods are said to be overloaded and the process is called method overloading. Method overloading is a way by which Java implements polymorphism.

Explanation: Array is object container which is used to hold a collection of fixed value having the same type.

Explanation: Short occupies 16 bits in memory. Its range is from -32768 to 32767.

The correct answer is "java.lang" because the java.lang package contains fundamental classes and interfaces that are essential to the Java programming language. String and StringBuffer classes are both part of this package, making it the superclass of both.

Explanation: The Void class has one field, TYPE, which holds a reference to the Class object for the type void.

Explanation: Data type long literals are appended by an upper or lowercase L. 0x99fffL is hexadecimal long literal.

Explanation: switch statements checks for equality between the controlling variable and its constant cases.

Explanation: None

Explanation: Memory is allocated to an object using new operator. box obj; just declares a reference to object, no memory is allocated to it hence it points to NULL

Explanation:

The correct answer is substring(). This method is used to extract a substring from a String object. It takes two parameters, the starting index and the ending index, and returns a new string that is a subset of the original string. The substring() method is case-sensitive and the ending index is exclusive, meaning it does not include the character at that index in the substring.

Explanation: Array class is a member of a java.util

Explanation: Char occupies 16-bit in memory, so it supports 2^16 i:e from 0 to 65535.

The method getChars() is used to extract more than one character at a time from a String object.

Explanation: Constructors does not have any return type, not even void.