Capgemini Java interview questions

The major features of Java are listed below: –

• Object-oriented: – Java language is based on object-oriented programming. In this, the class and the methods describe the state and behavior of an object. The programming is done by relating a problem with the real world object.
• Portable: – the conversion of java program into Java bytecodes take place. This helps in running the program in any environment or platform without any dependency.
• Platform independent: – java ensures “write once run anywhere” as its programs can be run on multiple platforms like- Windows, Mac, Sun Solaris, Linux, etc.
• Robust: – java’s strong memory due to no pointer allocations, make it robust. The memory leaks are prohibited with the help of automatic garbage collection in java.
• Interpreted: – the java code is converted into bytecodes by the java compiler which is then interpreted and executed by the Java interpreter or a just-in-time compiler (JIT).

Difference between Class and object In JAVA:

• Class - A class is like a blueprint. It is the class with the help of which objects are created. The class holds together data and methods in one single unit. And the class needs to be declared only a single time.
• Object - This is an instance of the class. It is with the help of an object that data and methods that exist within a class can be used. Objects can be called upon several times as and when required.

Inversion of control is a design pattern that is used for decoupling components and layers of a system. Inversion of control(IOC) is implemented through injecting dependencies into a component when it is constructed.

A number that is divisible by 1 or itself is a Prime Number. 2, 3, 5, 7, 11, 13, 17 are examples of some Prime numbers.

Please Note: 0 and 1 are not a prime number.

Below is a simple Prime number Program in Java to check a number is Prime or Not.

import java.util.Scanner;
public class PrimeExample {
 public static void main(String args[]) {
  int i, m = 0, flag = 0;
  Scanner scan = new Scanner(System.in);
  System.out.print("Enter any number: ");
  // This method reads the number provided using keyboard
  int num = scan.nextInt();
  // Closing Scanner after the use
  scan.close();
  m = num / 2;
  if (num == 0 || num == 1) {
   System.out.println(num + " is not prime number");
  } else {
   for (i = 2; i <= m; i++) {
    if (num % i == 0) {
     System.out.println(num + " is not prime number");
     flag = 1;
     break;
    }
   }
   if (flag == 0) {
    System.out.println(num + " is prime number");
   }
  } //end of else
 }
}