Core Java Interview Questions and Answers: Question 71 to Question 90
Here you can find the 100+ most frequently asked important core java interview questions and answers (71 to 90) for placement (campus) interview and competitive examinations.
71. What is the return type of a program’s main() method?
72. If a variable is declared as private, where may the variable be accessed?
Answer: A private variable may only be accessed within the class in which it is declared.
73. What do you understand by private, protected and public?
Answer: These are accessibility modifiers. Private is the most restrictive, while the public is the least restrictive. There is no real difference between protected and the default type (also known as package protected) within the context of the same package, however, the protected keyword allows visibility to a derived class in a different package.
74. What is Downcasting ?
Answer: Downcasting is the casting from a general to a more specific type, i.e. casting down the hierarchy
75. What modifiers may be used with an inner class that is a member of an outer class?
Answer: A (non-local) inner class may be declared as public, protected, private, static, final, or abstract.
76. What restrictions are placed on the location of a package statement within a source code file?
Answer: A package statement must appear as the first line in a source code file (excluding blank lines and comments).
77. What is a native method?
Answer: A native method is a method that is implemented in a language other than Java.
78. What are order of precedence and associativity, and how are they used?
Answer: Order of precedence determines the order in which operators are evaluated in expressions. Associativity determines whether an expression is evaluated left-to-right or right-to-left.
79. Can an anonymous class be declared as implementing an interface and extending a class?
Answer: An anonymous class may implement an interface or extend a superclass, but may not be declared to do both.
80. What is the range of the char type?
Answer: The range of the char type is 0 to 216 – 1 (i.e. 0 to 65535.)
81. What is the range of the short type?
Answer: The range of the short type is -(215) to 215 – 1. (i.e. -32,768 to 32,767)
82. Why isn’t there operator overloading?
Answer: Because C++ has proven by example that operator overloading makes code almost impossible to maintain.
83. What does it mean that a method or field is “static”?
Answer: Static variables and methods are instantiated only once per class. In other words, they are class variables, not instance variables. If you change the value of a static variable in a particular object, the value of that variable changes for all instances of that class. Static methods can be referenced with the name of the class rather than the name of a particular object of the class (though that works too). That’s how library methods like System.out.println() work. out is a static field in the java.lang.System class.
84. Is null a keyword?
Answer: The null value is not a keyword.
85. Which characters may be used as the second character of an identifier, but not as the first character of an identifier?
Answer: The digits 0 through 9 may not be used as the first character of an identifier but they may be used after the first character of an identifier.
86. Is the ternary operator written x : y ? z or x ? y : z ?
Answer: It is written x ? y : z.
87. How is rounding performed under integer division?
Answer: The fractional part of the result is truncated. This is known as rounding toward zero.
88. If a class is declared without any access modifiers, where may the class be accessed?
Answer: A class that is declared without any access modifiers is said to have package access. This means that the class can only be accessed by other classes and interfaces that are defined within the same package.
89. Does a class inherit the constructors of its superclass?
Answer: A class does not inherit constructors from any of its superclasses.
90. How many bits are used to represent Unicode, ASCII, UTF-16, and UTF-8 characters?
Answer: Unicode requires 16 bits and ASCII requires 7 bits Although the ASCII character set uses only 7 bits, it is usually represented as 8 bits. UTF-8 represents characters using 8, 16, and 18-bit patterns. UTF-16 uses 16-bit and larger bit patterns.
Here you can find the 100+ frequently asked important Core Java Interview Questions and Answers 71 to 90. If you like the material share it with your friends. Like the Facebook page for regular updates and YouTube channel for video tutorials.