Top 100 Java Fresher programing Interview Question

1. Write a program to read a String value from user and display it

package com.java4us;

import java.util.Scanner;

public class Program01 {

    public static void main(String[] args) {
        System.out.println("---Read a String value and display---");
        System.out.println("Please enter input value:- ");
        Scanner scanner = new Scanner(System.in);
        String input = scanner.next();
        System.out.println("Enter input value is: " + input);
    }
}

2. Write a program to read a integer value from user and display it

package com.java4us;

import java.util.Scanner;

public class Program02 {
    public static void main(String[] args) {
        System.out.println("---Read a integer value and display---");
        System.out.println("Please enter input value:- ");
        Scanner scanner = new Scanner(System.in);
        Integer input_value = scanner.nextInt();
        System.out.println("User input value is: " + input_value);
    }
}

3. Write a program to read a String value from user and display its individual charactor

package com.java4us;

import java.util.Scanner;

public class Program03 {

    public static void main(String[] args) {
        System.out.println("---Read a String value and display its individual charactor---");
        System.out.println("Please enter input value:- ");
        Scanner scanner = new Scanner(System.in);
        String input_value = scanner.next();
        for (int i = 0; i < input_value.length(); i++) {
            System.out.println(i + " charactor of given input is:- " + input_value.charAt(i));

        }
    }
}

4. Write a program to read one char value from user and display it

package com.java4us;

import java.util.Scanner;

public class Program04 {
    public static void main(String[] args) {
        System.out.println("---Read a String value and display first charactor---");
        System.out.println("Please enter input value:- ");
        Scanner scanner = new Scanner(System.in);
        char first_char = scanner.next().charAt(0);
        System.out.println("First charactor of given input is:- " + first_char);
    }
}

5. Write a program to read two numbers and swap them using third variable

package com.java4us;

import java.util.Scanner;

public class Program05 {
    public static void main(String[] args) {
        System.out.println("---Swaping with using Third variable---");
        System.out.println("Please enter First value:- ");
        Scanner scanner1 = new Scanner(System.in);
        int value1 = scanner1.nextInt();
        System.out.println("Please enter Second value:- ");
        Scanner scanner2 = new Scanner(System.in);
        int value2 = scanner2.nextInt();
        System.out.println("Value before swaping: " + value1 + "-" + value2);
        int temp = 0;
        temp = value1;
        value1 = value2;
        value2 = temp;
        System.out.println("Value after swaping: " + value1 + "-" + value2);
    }
}

6. Write a program to read two numbers and swap them without using third variable

package com.java4us;

import java.util.Scanner;

public class Program06 {
    public static void main(String[] args) {
        System.out.println("---Swaping without using Third variable---");
        System.out.println("Please enter first value");
        Scanner scannner1 = new Scanner(System.in);
        int value1 = scannner1.nextInt();
        System.out.println("Please enter second value");
        Scanner scannner2 = new Scanner(System.in);
        int value2 = scannner2.nextInt();
        System.out.println("Input value before swaping:- " + value1 + ":" + value2);
        value1 = value1 + value2;
        value2=value1-value2;
        value1 = value1 - value2;
        System.out.println("Input value after swaping:- " + value1 + ":" + value2);
        
    }
}

7. Write a program to read two numbers and swap them using bitwise operator

package com.java4us;

import java.util.Scanner;

public class Program07 {

    public static void main(String[] args) {
        System.out.println("---Swaping using bitwise operator---");
        System.out.println("Please enter first value");
        Scanner scannner1 = new Scanner(System.in);
        int value1 = scannner1.nextInt();
        System.out.println("Please enter second value");
        Scanner scannner2 = new Scanner(System.in);
        int value2 = scannner2.nextInt();
        System.out.println("Input value before swaping:- " + value1 + ":" + value2);
        value1 = value1 ^ value2;
        value2 = value1 ^ value2;
        value1 = value1 ^ value2;
        System.out.println("Input value after swaping:- " + value1 + ":" + value2);
    }
}

8. Write a program to read two numbers and display sum.

package com.java4us;

import java.util.Scanner;

public class Program08 {
    public static void main(String[] args) {
        System.out.println("---Read two number and display sum of those two number---");
        System.out.println("Please enter first value");
        Scanner scannner1 = new Scanner(System.in);
        int value1 = scannner1.nextInt();
        System.out.println("Please enter second value");
        Scanner scannner2 = new Scanner(System.in);
        int value2 = scannner2.nextInt();
        System.out.println("Sum of user entered value:- " + (value1 + value2));
    }
}

9. Write a program to read two number and display sum without using + Operator

package com.java4us;

import java.util.Scanner;

public class Program09 {
    public static void main(String[] args) {
        System.out.println("---Read two number and display sum without using airthmetic operator---");
        System.out.println("Please enter first value");
        Scanner scannner1 = new Scanner(System.in);
        int value1 = scannner1.nextInt();
        System.out.println("Please enter second value");
        Scanner scannner2 = new Scanner(System.in);
        int value2 = scannner2.nextInt();
        while (value2 != 0) {

            int carry = value1 & value2;

            value1 = value1 ^ value2;

            value2 = carry << 1;
        }
        System.out.println("sum = " + value1);
    }
}

10. Write a program to convert Fahrenheit to Celsius

package com.java4us;

import java.util.Scanner;

public class Program10 {
    public static void main(String[] args) {
        System.out.println("---Program to convert fahrenheit to Celsius---");
        Scanner scanner = new Scanner(System.in);
        System.out.println("Please enter fahrenheit value");
        int fahrenheit = scanner.nextInt();
        int Celsius = (fahrenheit - 32) * 5 / 9;
        System.out.println("Celsious value for corresponding fahrenheit " + fahrenheit + " value is :- " + Celsius);
    }
}

11. Write a program to read a number and display whether the number is positive or nagative.

package com.java4us;

import java.util.Scanner;

public class Program11 {
    public static void main(String[] args) {
        System.out.println("---Program to check user entered value is Positive or Negative---");
        System.out.println("Please enter the value");
        Scanner scanner = new Scanner(System.in);
        int value = scanner.nextInt();
        if (value >= 0) {
            System.out.println("Entered value is Positive " + value);
        } else
            System.out.println("Entered value is Negetive " + value);
    }
}

12. Write a program to read age of person and display whether he/she eligible for voting or not

package com.java4us;

import java.util.Scanner;

public class Program12 {
    public static void main(String[] args) {
        System.out.println("---Program to check user is eligible for voting or not---");
        System.err.println("Please enter your current age");
        Scanner scanner = new Scanner(System.in);
        int age = scanner.nextInt();
        if (age >= 18) {
            System.out.println("You are eligible for vote");
        } else
            System.out.println("You are not eligble for vote");
    }
}

13. Write a program to read number and display whether the number is even or odd.

package com.java4us;

import java.util.Scanner;

public class Program13 {
    public static void main(String[] args) {
        System.out.println("---Program to check user entered value is even or odd---");
        System.out.println("Please enter value");
        Scanner scanner = new Scanner(System.in);
        int value = scanner.nextInt();
        if (value % 2 == 0) {
            System.out.println("User entered value is even");
        } else
            System.out.println("User entered value is odd");
    }
}

14. Write a program to read two number and display the maximum.

package com.java4us;

import java.util.Scanner;

public class Program14 {
    public static void main(String[] args) {
        System.out.println("---Program to check maximum digit from two enter value---");
        System.out.println("Please enter first digit");
        Scanner scanner = new Scanner(System.in);
        int value1 = scanner.nextInt();
        System.out.println("Please enter second digit");
        int value2 = scanner.nextInt();
        if (value1 < value2) {
            System.out.println(value2 + " is greater then value " + value1);
        } else if (value1 > value2) {
            System.out.println(value1 + " is greater then value " + value2);
        } else
            System.out.println(value1 + " both are equal " + value2);
    }
}

15. Write a program to read two number and display the minimum.

package com.java4us;

import java.util.Scanner;

public class Program15 {

    public static void main(String[] args) {
        System.out.println("---Program to check minimum digit from two enter value---");
        System.out.println("Please enter first digit");
        Scanner scanner = new Scanner(System.in);
        int value1 = scanner.nextInt();
        System.out.println("Please enter second digit");
        int value2 = scanner.nextInt();
        if (value1 < value2) {
            System.out.println(value1 + " is less then value " + value2);
        } else if (value1 > value2) {
            System.out.println(value2 + " is less then value " + value1);
        } else
            System.out.println(value1 + " both are equal " + value2);
    }
}

16. Write a program to read three numbers and display the maximum.

package com.java4us;

import java.util.Scanner;

public class Program16 {
    public static void main(String[] args) {
        System.out.println("---Program to read three digit and display maximum---");
        System.out.println("Please enter first digit");
        Scanner scanner = new Scanner(System.in);
        int value1 = scanner.nextInt();
        System.out.println("Please enter second digit");
        int value2 = scanner.nextInt();
        System.out.println("Please enter third digit");
        int value3 = scanner.nextInt();
        if (value1>value2&&value1>value3) {
            System.out.println(value1+" is maximum value");
        }
        else if (value2 > value1 && value2 > value3) {
            System.out.println(value2+" is maximum value");
        }
        else
            System.out.println(value3 + " is maximum value");
    }
}

17. Write a program to read three numbers and display the minimum.

package com.java4us;

import java.util.Scanner;

public class Program17 {

    public static void main(String[] args) {
        System.out.println("---Program to read three digit and display minimum---");
        System.out.println("Please enter first digit");
        Scanner scanner = new Scanner(System.in);
        int value1 = scanner.nextInt();
        System.out.println("Please enter second digit");
        int value2 = scanner.nextInt();
        System.out.println("Please enter third digit");
        int value3 = scanner.nextInt();
        if (value1 < value2 && value1 < value3) {
            System.out.println(value1 + " is minimum value");
        } else if (value2 < value1 && value2 < value3) {
            System.out.println(value2 + " is minimum value");
        } else
            System.out.println(value3 + " is minimum value");
    }
}

18. Write a program to read a char and display whether it is digit or not.

package com.java4us;

import java.util.Scanner;

public class Program18 {

    public static void main(String[] args) {
        System.out.println("---Program to read a charactor and check whether its a digit or not---");
        System.out.println("Please enter charactor value");
        Scanner scanner = new Scanner(System.in);
        char ch = scanner.next().charAt(0);
        if (ch >= 65 && ch <= 90 || ch >= 97 && ch <= 122) {
            System.out.println("Enter digit is charactor");
        } else
            System.out.println("Enter digit is not charactor");
    }
}

19. Write a program to read a char and display whether it is uppercase alphabet or not.

package com.java4us;

import java.util.Scanner;

public class Program19 {

    public static void main(String[] args) {
        System.out.println("---Program to read a charactor and check whether its a uppercase alphabet or not---");
        System.out.println("Please enter charactor value");
        Scanner scanner = new Scanner(System.in);
        char ch = scanner.next().charAt(0);
        if (ch >= 65 && ch <= 90) {
            System.out.println("Enter digit is Upper case alphabet");
        } else
            System.out.println("Enter digit is not Upper case alphabet");
    }
}

20. Write a program to read a char and display whether it is lowercase alphabet or not.

package com.java4us;

import java.util.Scanner;

public class Program20 {

    public static void main(String[] args) {
        System.out.println("---Program to read a charactor and check whether its a lowercase alphabet or not---");
        System.out.println("Please enter charactor value");
        Scanner scanner = new Scanner(System.in);
        char ch = scanner.next().charAt(0);
        if (ch >= 97 && ch <= 122) {
            System.out.println("Enter digit is Lower case alphabet");
        } else
            System.out.println("Enter digit is not lower case alphabet");
    }
}