Abstract Classes

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Abstract Classes

Abstract class is basically never be instantiated. its mainly purpose of the mission of life .that\'s the soul purpose of them . 
We have a code for the abstract class : 

abstract class Car {
private double price;
private Color carColor;
private String model;
private String year;
public abstract void goFast();
public abstract void goUpHill();
public abstract void impressNeighbors();
// Additional, important, and serious code goes here
}

When we execute this code its working fine .but when ever we instantiated  car in th another body of code its gives us a compiler error : 
AnotherClass.java:7: class Car is an abstract
class. It can\'t be instantiated.
Car x = new Car();
1 error

More interview questions and answers
Initializing Elements in a Loop
Declaring, Constructing, and Initializing on One Line
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { int x, y; int z = 4; z++; y = 3; y++; z = y = z = 2; System.out.println("Value of z is = "+z ); } }
Constructing and Initializing an Anonymous Array
Arrays of Primitives
Arrays of Object References
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { int x, y; int z = 4; z++; y = 4; y++; z+= y-= x = 2; if( z == 6) z-= 3; else z+= 3; System.out.println("Value of z is "+z ); } }
Array Reference Assignments for One-Dimensional Arrays
Array Reference Assignments for Multidimensional Arrays
Using a Variable or Array Element That Is Uninitialized and Unassigned
What result comes when we compile and run following code: public class R4RSCJPTest { int i = 1; public static void main(String args[]) { int i = 2; i = new_i(i); System.out.println("New value of i is " +i); } public static int new_i(int i) { i = 3; i *= 4; return i; } }
What result comes when we compile and run following code: public class R4RSCJPTest { int i = 1; public static void main(String args[]) { int i = 2; new_i(i); System.out.println("New value of i is " +i); } public static void new_i(int i) { i = 3; i *= 4; } }
What result comes when we compile and run following code: public class R4RSCJPTest { int i[] = {0}; public static void main(String args[]) { int i[] = {1}; new_i(i); System.out.println("New value of i[0] is " +i[0]); } public static void new_i(int i[]) { i[0] = 2; i[0] *= 3; } }
What result comes when we compile and run(with command line argument R4R welcome in intellegence world. in following code: public class R4RSCJPTest { public static void main(String args[]) { System.out.println(args[0]+" "+args [args.length-1]); } }
What result comes when we compile and run(with command line argument like: R4R welcomes you in intelligence world) following code: public class test { public static void main(String args[]) { System.out.println(args[0]+" "+args.length); } }
What result comes when we compile and run following code: class R4RSCJPTest { public static void main(String args[]) { int i,j,k,l=0; k = l++; j = ++k; i = --j; System.out.println("Value of i is " +i); } }
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { char c; int i; c = 'A'; //1 i = c; //2 c = i + 1; //3 i++; //4 } }
Select correct signed of left shift operator.
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { int i = 1; boolean t = true; boolean f = false, boo; boo = (t && ((i++) == 0)); boo = (f && ((i+=2) > 0)); System.out.println("Value of i is " +i); } }
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { int i = 1; boolean t = true; boolean f = false, boo; boo = (t & ((i++) == 0)); boo = (f & ((i+=2) > 0)); System.out.println("Value of i is " +i); } }
Primitive Instance Variables
Object Reference Instance Variables
Array Instance Variables
Local Primitives
Local Objects
Local Arrays
Command-Line Arguments to Main
Declarations and Modifiers
Class Declarations and Modifiers
Class Access
Default Access
Public Access
Other (Nonaccess) Class Modifiers
Final Classes
Abstract Classes
Creating an Abstract Superclass and Concrete Subclass
Method and Variable Declarations and Modifiers.
Member Access
Public Members
Private Members
Local Variables and Access Modifiers
Nonaccess Member Modifiers
Final Methods
Final Arguments
What result comes when we compile and following code: public class R4RSCJPTest { public static void main(String args[]) { byte i = 4; i = (byte)~i; System.out.println("Value of i is " +i); } }
Select operator which we use in Java for bitwise inversion.
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { int i,j; i = 1 & 5; j = 2 \| 7; System.out.println("Value of i is " + i + ", Value of j is " + j ); } }
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { int i = -1; int j = i>>3; int k = j & 129; System.out.println("Value of k is " +k); } }
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { int i,j; i = 1 \| 5 ; j = 2 ^ 7; System.out.println("Value of i is " + i + ", Value of j is " + j); } }
Synchronized Methods
Native Methods
Strictfp Methods
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { boolean boo = true; int i; if(boo) i = boo ? 3: 2; else i = boo ? 4: 1; System.out.println("Value of i is " +i); } }
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { boolean boo = false; int i; if(boo) i = boo ? 3: 2; else i = boo ? 4: 1; System.out.println("Value of i is " +i); } }
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { int i = 0; if(i < 0) i = 1; switch(i) { case 2: System.out.println(2); case 0: System.out.println(0); case 1: System.out.println(1); break; case 3: System.out.println(3); default: System.out.println(4); break; } } }
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { int i, j; i = 7 >> 2; j = 7 >>> 2; System.out.println("Value of i is " +i+",Value of j is " +j); } }
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { int i; i = -2 << 1; i = i >> 3; i = i >>> 2; System.out.println("Value of i is " +i); } }
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { int i; i = -2 << 1; i = i >>> 2; i = i >> 1; System.out.println("Value of i is " +i); } }
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { int i = -4; i = i << 2; System.out.println("Value of i is " +i); } }
Select correct signed right shift operator from following.
Select shift operator which are not used in Java.
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { int i = 0, J = 1, k; if(i) k = 2; else k = 1; if(j) k = 0; else k = 3; System.out.println("Value of k is " +k); } }
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { for(int i = 0; i < 2; i++) { for(int j = 1; j >= 0; j--) { if(i == j) continue; System.out.println("Value of i is "+ i + ", Value of j is " + j); } } } }
What result comes when we compile and run following code: public class Test { public static void main(String args[]) { for(int i = 0; i < 2; i++) { for(int j = 1; j >= 0; j--) { if(i == j) break; System.out.println("Value of i is "+ i + ", Value of j is " + j); } } } }
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { outer: for(int i = 0; i < 2; i++) { for(int j = 2; j >= 0; j--) { if(i == j) continue outer; System.out.println("Value of i is " +i+ ", Value of j is " +j); } } } }
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { outer: for(int i = 0; i < 2; i++) { for(int j = 2; j >= 0; j--) { if(i == j) break outer; System.out.println("Value of i is " +i+ ", Value of j is " +j); } } } }
Variable Declarations
Instance Variables
Local (Automatic/Stack/Method) Variables
Final Variables
Transient Variables
Volatile Variables
Static Variables and Methods
Accessing Static Methods and Variables
Declaration Rules
Source File Structure
Using Import Statements
Formatting the main() Method
Interface Implementation
Declaring an Interface
Declaring Interface Constants
Implementing an Interface
What result comes when we compile and run following code: class Test { public static void main(String args[]) { int arr[] = new int[2]; System.out.println(arr[0]); } }
Select legal declaration and defination of a method.
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { int i = 1; int j = 0; boolean boo = true; boolean boo1; boo1 = (boo && 0<(i+=2)); boo1 = (boo && 0<(i+=1)); boo1 = (boo && 0<(j+=2)); boo1 = (boo \|\| 0<(j+=1)); System.out.println("Value of i is " + i + ", Value of j is " + j ); } }
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { int i = 1; int j = 0; boolean boo = false; boolean boo1; boo1 = (boo && 0<(i+=2)); boo1 = (boo && 0<(i+=1)); boo1 = (boo && 0<(j+=2)); boo1 = (boo \|\| 0<(j+=1)); System.out.println("Value of i is " + i + ", Value of j is " + j ); } }
What result comes when we compile and run following code: public class R4RSCJPTest { public static void main(String args[]) { char A = '\u0005'; if ( A == 0x0005L ) System.out.println("Equal"); else System.out.println("Not Equal"); } }
What result comes when we compile and run following code: class R4RSCJPTest { public void methodTest(int i) { System.out.println("Value of i is " +i); } public int methodTest(int i) { System.out.println("Value of i+1 is " + (i+1)); return (i+1); } public static void main(String args[]) { R4RSCJPTest a = new R4RSCJPTest(); a.methodTest(4); } }
What result comes when we compile and run following code: class R4RSCJPTest { public static void main(String arg[]) { int a[]={2,2}; int b=0; a[b]=b=1; System.out.println(a[0]); System.out.println(a[1]); } }
Select two valid character contants from followings.
Select correct statement to execute given program: public class R4RSCJPTest { int planets; static int suns; public void gaze() { int i; // .... write statements here .... } }
Select all valid statement from followings.
Select the valid ways which refer to the class from outside the package net.codemaster. package net.codemaster; public class code { // ...Write some statements here... }
public class myprog { public static void main(String [] args) { signed int a = 20; for (int b=0; b<10; b++, a--) System.out.print(" " + a); } }
What result comes when we compile and run following code: protected class R4RSCJPTest { public static void main(String args[]) { String str1 = "xyz", str2 = "pqr",str; str = str1 + str2; System.out.println(str); } }
Which word is reserved word in the Java programming language in the following option?
Which one of these lists contains only Java programming language keywords?
Which two are keywords?
A top level class without any modifier is accessible by....... (Select most appropriate answer)
Which three are valid declarations of a char?