JAVA PRACTICE EXAM QUESTIONS WITH 100% VERIFIED ANSWERS

JAVA PRACTICE EXAM QUESTIONS
WITH 100% VERIFIED ANSWERS

What is a compound assignment operator? - Answer- You can also combine the
arithmetic operators with the simple assignment operator to create compound
assignments. For example, x+=1; and x=x+1; both increment the value of x by 1.

The most basic control flow statement supported by the Java programming language is
the ___ statement. - Answer- if then

The ___ statement allows for any number of possible execution paths. - Answer- switch

The ___ statement is similar to the while statement, but evaluates its expression at the
___ of the loop. - Answer- do while
end

How do you write an infinite loop using the for statement? - Answer- for ( ; ; ) {
//do something
}

How do you write an infinite loop using the while statement? - Answer- while (true) {
//do something
}

Consider the following code snippet.

if (aNumber >= 0)
if (aNumber == 0)
System.out.println("first string");
else
System.out.println("second string");
System.out.println("third string");

Exercise: What output do you think the code will produce if aNumber is 3? - Answer-
second string
third string

"this" keyword - Answer- Within an instance method or a constructor, this is a reference
to the current object — the object whose method or constructor is being called. You can
refer to any member of the current object from within an instance method or a
constructor by using this. The most common reason for using the this keyword is
because a field is shadowed by a method or constructor parameter.

, public class Point {
public int x = 0;
public int y = 0;

//constructor
public Point(int x, int y) {
this.x = x;
this.y = y;
}
}

Each argument to the constructor shadows one of the object's fields — inside the
constructor x is a local copy of the constructor's first argument. To refer to the Point field
x, the constructor must use this.x.

"private" modifier - Answer- The private modifier specifies that the member can only be
accessed in its own class.

"protected" modifier - Answer- The protected modifier specifies that the member can
only be accessed within its own package (as with package-private) and, in addition, by a
subclass of its class in another package.

What happens if a class has no modifier? - Answer- If a class has no modifier (the
default, also known as package-private), it is visible only within its own package
(packages are named groups of related classes)

"static" modifier - Answer- Sometimes, you want to have variables that are common to
all objects. This is accomplished with the static modifier. Fields that have the static
modifier in their declaration are called static fields or class variables. They are
associated with the class, rather than with any object. Every instance of the class
shares a class variable, which is in one fixed location in memory. Any object can
change the value of a class variable, but class variables can also be manipulated
without creating an instance of the class.

Class variables are referenced by the class name itself (not an object name), as in

Bicycle.numberOfBicycles

This makes it clear that they are class variables rather than instance variables.

"final" modifier - Answer- use "final" to create a constant. The static modifier, in
combination with the final modifier, is also used to define constants. The final modifier
indicates that the value of this field cannot change.

For example, the following variable declaration defines a constant named PI, whose
value is an approximation of pi (the ratio of the circumference of a circle to its diameter):