JAVA practice questions and example answers

Question 1:-

//Code for question 1class Student{ int age=0; char gender; double maths; double stat; double cs; //double avg; double calAvg(){ return (this.maths+this.stat+this.cs)/3; } } class Driver1{ public static void main(String[]arg){ Student st1=new Student(); st1.age=30; st1.gender='M'; st1.maths=45; st1.stat=78; st1.cs=90; System.out.println("Student 1 :"+st1.calAvg()); Student st2=new Student(); st2.age=80; st2.gender='F'; st2.maths=90; st2.stat=7; st2.cs=36; System.out.println("Student 2 :"+st2.calAvg()); } }

//A advanced code for question 1import java.util.*; class Student{ int age=0; String gender; double maths; double stat; double cs; //double avg; double calAvg(){ return (this.maths+this.stat+this.cs)/3; } } class Driver1_extend{ public static void main(String[]arg){ Scanner sc=new Scanner(System.in); Student st1=new Student(); System.out.print("Enter the age of first Student...."); st1.age=sc.nextInt(); sc.nextLine();/*For fix a logical error*/ System.out.print("Enter the gender of first Student...."); st1.gender=sc.nextLine(); System.out.print("Enter the mathamatics marks of of first Student...."); st1.maths=sc.nextDouble(); System.out.print("Enter the stat marks of first Student...."); st1.stat=sc.nextDouble(); System.out.print("Enter the computer science marks of first Student...."); st1.cs=sc.nextDouble(); System.out.println("Student 1 :"+st1.calAvg()); Student st2=new Student(); st2.age=80; //st2.gender='F'; st2.maths=90; st2.stat=7; st2.cs=36; System.out.println("Student 2 :"+st2.calAvg()); } }

Question 2

Code for question 2:import java.util.*; class Calculator{ double num1; double num2; } class GetNumbers{ void getting(){ Scanner sc=new Scanner(System.in); Calculator cal=new Calculator(); System.out.print("Enter the first no...."); cal.num1=sc.nextDouble(); System.out.print("Enter the second no...."); cal.num2=sc.nextDouble(); Choice ch=new Choice(); ch.choose(cal.num1,cal.num2); }

} class Choice{ void choose(double num1,double num2){ Scanner sc=new Scanner(System.in); int choice; System.out.println("1- Addition\n 2-Substraction \n 3-Division \n 4-Multiplication"); System.out.print("Enter the choice No....."); choice=sc.nextInt(); if(choice==1){ Addition add=new Addition(); System.out.println(add.add(num1,num2)); } if(choice==2){ Substraction sub=new Substraction(); System.out.println(sub.sub(num1,num2)); } if(choice==3){ Division div=new Division(); System.out.println(div.div(num1,num2)); }

if(choice==4){ Multiplication mul=new Multiplication(); System.out.println(mul.mul(num1,num2)); } } }

class Addition{ double add(double num1,double num2){ return num1+num2; } } class Substraction{ double sub(double num1,double num2){ return num1-num2; } } class Division{ double div(double num1,double num2){ return num1+num2; } } class Multiplication{ double mul(double num1,double num2){ return num1*num2; } }

class Driver2{ public static void main(String[]arg){ GetNumbers gn=new GetNumbers(); gn.getting(); } }

Question 3:-

Code for question 3:import java.util.*; class InsertValues{ private double length=1; private double width=1; private double height=1; public void setValues(double length,double width,double height){ this.length=length; this.width=width; this.height=height; } public void cubeVolume(){ System.out.println("Volume of the cube is...."+length*height*width); } public void cubeArea(){ System.out.println("Area of the cube is..."+(length*width)*6); } } class Driver3{ public static void main(String[]arg){ for(int count=1;count>0;count++){ Scanner sc=new Scanner(System.in); InsertValues val=new InsertValues(); System.out.print("Enter the values for height..."); double height=sc.nextDouble(); System.out.print("Enter the values for width..."); double width=sc.nextDouble(); System.out.print("Enter the values for length..."); double length=sc.nextDouble(); val.setValues(length,width,height); val.cubeVolume(); val.cubeArea(); } } }

Question 4:-

Code for question 4:class FindAverage{ int average(int val1,int val2){ return (val1+val2)/2; } int average(int val1,int val2,int val3){ return (val1+val2+val3)/3; } float average(int val1,float val2){ return (val1+val2)/2; } float average(int val1,int val2,float val3){ return (val1+val2+val3)/3; } float average(float val1,float val2,float val3){ return (val1+val2+val3)/3; } double average(double val1,double val2){ return (val1+val2)/2; } double average(int val1,float val2,double val3){ return (val1+val2+val3)/3; } } class Driver5{ public static void main(String[]arg){ FindAverage fA=new FindAverage(); System.out.println(fA.average(2,4)); System.out.println(fA.average(2,4,5)); System.out.println(fA.average(2,5f)); System.out.println(fA.average(2,4,5.4f)); System.out.println(fA.average(2.56f,4.5f,5f)); System.out.println(fA.average(2.54,4.3)); System.out.println(fA.average(2,4f,5.34)); } }

Question 5:-

Code for Question 5:import java.util.*; class StudentMarks{ public void markPanal(int stu){ int marks[]=new int[5]; int value=0; Scanner sc=new Scanner(System.in); for(int markIndex=0;markIndex