- What restrictions are placed on the location of a package statement within a source code file?
A package statement must appear as the first line in a source code file (excluding blank lines and comments).
- What is a native method?
A native method is a method that is implemented in a language other than java.
- What is order of precedence and associatively, and how are they used?
Order of precedence determines the order in which operators are evaluated in expressions. Associatlity determines whether an expression is evaluated left-to-right or right-to-left.
- Can an anonymous class be declared as implementing an interface and extending a class?
An anonymous class may implement an interface or extend a superclass, but may not be declared to do both.
- What is the range of the char type?
The range of the char type is 0 to 2^16-1(i.e. 0 to 65535).
- What is the range of the short type?
The range of the short type is –(2)^15 to 2^15-1. (i.e. -32768 to 32767)
- Why isn’t there operator overloading?
Because C++ has proven by example that operator overloading marks code almost impossible to maintain.
- What does it mean that a method or field is “static”?
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.
- Is null a keyword?
The null value is not a keyword.
- Which characters may be used as the second character of an identifier, but not as the first character of an identifier?
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.
- Is the ternary operator written x:y?z or x?y:z?
It is written x?y:z
- How is rounding performed under integer division?
The fractional part of the result is truncated. This is known as rounding towards zero.
- If a class is declared without any process modifiers, where may the class be accessed?
A class that is declared without any access modifiers is said to have package access. This means that the class only be accessed by other classes and interfaces that are defined within the same package.