Java Programming Lab
1. Write a java program to print a message "Hello World"
// Java Program to print "Hello World" message
Program
Sample.java
import java.io.*;
class Sample
{
public static void main(String[] args)
{
System.out.println("Hello World");
}
}
1. Save the file name with Sample with an extension .java. i.e., Sample.java
2. Compile the program with the command javac.
javac Sample.java
3. Then the java compiler translates the source code into byte code which is understandable by the JVM.
4. After compilation process, you get the .class with the class name defined in your java program.
5. In the above program you have only one class Sample so, Sample.class file created after compilation process.
6. Execute the java program with the command java.
7. java Sample then it executes the java program. Here, you should give the class name which has main().
Output:
2. Write a java program to perform addition of two numbers
Program
Addition.java
//java program to add two numbers
import java.io.*;
import java.util.*;
class Addition
{
public static void main(String[] args)
{
int a,b,sum;
Scanner sc=new Scanner(System.in);
System.out.println("Enter a and b values");
a=sc.nextInt();
b=sc.nextInt();
sum=a+b;
System.out.println("Addition of "+a+" and"+b+" is"+sum);
}
}
Output:
3. Write a java program to find Area and Perimeter of a Rectangle
Program
RectArea.java
//java program to find area and perimeter of a rectangle
import java.io.*;
import java.util.*;
class RectArea
{
public static void main(String[] args)
{
float len,bre,area,peri;
Scanner sc=new Scanner(System.in);
System.out.println("Enter length and breadth of a rectangle");
len=sc.nextFloat();
bre=sc.nextFloat();
area=len*bre;
peri=2*(len+bre);
System.out.println("Area of a rectangle is: "+area);
System.out.println("Perimeter of a rectangle is: "+peri);
}
}
Output:
4. Write a java program to read a string from the keyboard
ReadString.java
Program
//Reading a string from the keyboard
import java.io.*;
import java.util.*;
class ReadString
{
public static void main(String[] args)
{
String st;
Scanner sc=new Scanner(System.in);
System.out.println("Enter a string");
st=sc.nextLine();
System.out.println("Given string is: "+st);
}
}
Output
AsciiChar.java
Program
//Get ASCII Value of a given character
import java.io.*;
import java.util.*;
class AsciiChar
{
public static void main(String[] args)
{
char ch;
Scanner sc=new Scanner(System.in);
System.out.println("Enter a character");
ch=sc.next().charAt(0);
int value=(int)ch;
System.out.println("ASCII Value of a given character "+ch+" is "+value);
}
}
Output:
Note: The next() method is used to read a word from the keyboard. There is no special method to read the character from the keyboard using Scanner class object. With the help of next method, you should read the string first and then call the charAt() method which returns the character of your desired index value. So, in the above program, we should store the character which is placed in the 0th index. Thatswhy pass the argument 0 to the charAt() method.
Program
import java.io.*;
import java.lang.*;
import java.util.*;
class Student
{
public static void main(String[] args)
{
String sname;
int rno,total=0;
int[] marks=new int[20];
float avg;
Scanner sc=new Scanner(System.in);
System.out.println("Enter roll number and student name");
rno=sc.nextInt();
sname=sc.next();
System.out.println("Enter three subject marks");
for(int i=0;i<3;i++)
{
marks[i]=sc.nextInt();
total=total+marks[i];
}
avg=total/3;
System.out.println("Roll Number: "+rno);
System.out.println("Student Name: "+sname);
System.out.println("Mathematics: "+marks[0]);
System.out.println("Physics: "+marks[1]);
System.out.println("Compter Science: "+marks[2]);
System.out.println("Total: "+total);
System.out.println("Average: "+avg);
}
}
Output
7. Program to find the given substring present in the original string or not
Program
class FindSubstring
{
public static void main(String[] args)
{
String str = "This is my first program in java";
String str1 = "program";
String str2 = "Programming";
boolean result = str.contains(str1);
if(result)
System.out.println(str1 + " is present in the string.");
else
System.out.println(str1 + " is not present in the string.");
result = str.contains(str2);
if(result)
System.out.println(str2 + " is present in the string.");
else
System.out.println(str2 + " is not present in the string.");
}
}
output:
8. Program to compare two strings
Program
import java.io.*;
import java.util.*;
public class CompareStrings
{
public static void main(String[] args)
{
String str1 = new String();
String str2 = new String();
Scanner sc=new Scanner(System.in);
System.out.println("enter two strings to compare");
str1=sc.nextLine();
str2=sc.nextLine();
if(str1.equals(str2))
System.out.println("Equal");
else
System.out.println("Not Equal");
}
}
Output
8. Program to replace the existing string by a given string
Program
import java.io.*;
public class ReplaceString
{
public static void main(String args[])
{
String str="This is my first program";
String rstr=str.replace("is","was");
System.out.println(rstr);
}
}
Output
9. Program to replace the character in the existing string by a given character
Program
public class ReplaceChar{
public static void main(String[] args)
{
String str = "This is my first program in java";
String rstr = str.replace('i', 'f');
System.out.println("Original string: " + str);
System.out.println("String after replacing a character: " + rstr);
}
}
Output
Note: you can observe in the above output, the character 'i' is replaced by 'f'
10. Program to count number of words in a given string
Program
import java.io.*;
class CountWords
{
public static void main(String[] args)
{
String str = "This is my first program in java";
int countWords = str.split("\\s").length;
System.out.println(countWords);
}
}
Output
11. Program to perform addition of two matrices
Program
import java.io.*;
import java.util.*;
class AddMatrices
{
public static void main(String[] args)
{
int m,n,p,q,i,j;
int a[][]=new int[10][10];
int b[][]=new int[10][10];
int c[][]=new int[10][10];
Scanner sc=new Scanner(System.in);
System.out.println("Enter size of Matrix A");
m=sc.nextInt();
n=sc.nextInt();
System.out.println("Enter size of Matrix B");
p=sc.nextInt();
q=sc.nextInt();
if((m==p)&&(n==q))
{
System.out.println("Enter elements into matrix A");
for(i=0;i<m;i++)
for(j=0;j<n;j++)
a[i][j]=sc.nextInt();
System.out.println("Enter elements into matrix B");
for(i=0;i<p;i++)
for(j=0;j<q;j++)
b[i][j]=sc.nextInt();
//LOGIC FOR MATRIX ADDITION
for(i=0;i<m;i++)
for(j=0;j<n;j++)
c[i][j]=a[i][j]+b[i][j];
System.out.println("Elements in Matrix A");
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
System.out.print(a[i][j]+"\t");
System.out.println("");
}
System.out.println("Elements in Matrix B");
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
System.out.print(b[i][j]+"\t");
System.out.println("");
}
System.out.println("Resultant Matrix C");
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
System.out.print(c[i][j]+"\t");
System.out.println("");
}
}
else
System.out.println("Matrix addition is not possible");
}
}
Output:
Program
import java.io.*;
import java.util.*;
class MulMatrices
{
public static void main(String[] args)
{
int m,n,p,q,i,j,k;
int a[][]=new int[10][10];
int b[][]=new int[10][10];
int c[][]=new int[10][10];
Scanner sc=new Scanner(System.in);
System.out.println("Enter size of Matrix A");
m=sc.nextInt();
n=sc.nextInt();
System.out.println("Enter size of Matrix B");
p=sc.nextInt();
q=sc.nextInt();
if((m==q)&&(n==p))
{
System.out.println("Enter elements into matrix A");
for(i=0;i<m;i++)
for(j=0;j<n;j++)
a[i][j]=sc.nextInt();
System.out.println("Enter elements into matrix B");
for(i=0;i<p;i++)
for(j=0;j<q;j++)
b[i][j]=sc.nextInt();
//LOGIC FOR MATRIX Multiplication
for(i=0;i<m;i++)
{
for(j=0;j<q;j++)
{
c[i][j]=0;
for(k=0;k<n;k++)
c[i][j]+=a[i][k]*b[k][j];
}
}
System.out.println("Elements in Matrix A");
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
System.out.print(a[i][j]+"\t");
System.out.println("");
}
System.out.println("Elements in Matrix B");
for(i=0;i<p;i++)
{
for(j=0;j<q;j++)
System.out.print(b[i][j]+"\t");
System.out.println("");
}
System.out.println("Resultant Matrix C");
for(i=0;i<m;i++)
{
for(j=0;j<q;j++)
System.out.print(c[i][j]+"\t");
System.out.println("");
}
}
else
System.out.println("Matrix Multiplication is not possible");
}
}
Output
11. Program to demonstrate use of Constructor
Program
import java.io.*;
class Student
{
int sno;
String sname;
Student(int sno,String sname)
{
this.sno=sno;
this.sname=sname;
}
void display()
{
System.out.println("Student Number: "+sno);
System.out.println("Student Name: "+sname);
}
}
class ConstructorDemo
{
public static void main(String[] args)
{
Student s1=new Student(101,"Bharathi");
Student s2=new Student(102,"Chatrapathi");
Student s3=new Student(103,"Johith");
Student s4=new Student(104,"Jahnavi");
System.out.println("First student Details");
s1.display();
System.out.println("Second student Details");
s2.display();
System.out.println("Third student Details");
s3.display();
System.out.println("Fourth student Details");
s4.display();
}
}
Output
Program
import java.io.*;
class MethodOverload
{
//area of a triangle
double area(double b,double h)
{
return (0.5*b*h);
}
//area of a rectangle
int area(int l,int b)
{
return(l*b);
}
//area of a circle
double area(double r)
{
return 3.14*r*r;
}
//area of a square
int area(int s)
{
return(s*s);
}
}
class MethodoverloadEx
{
public static void main(String[] args)
{
MethodOverload mo=new MethodOverload();
System.out.println("Area of a triangle: "+mo.area(3.4,4.5));
System.out.println("Area of a Rectangle: "+mo.area(3,4));
System.out.println("Area of a Circle: "+mo.area(4.5));
System.out.println("Area of a Square: "+mo.area(5));
}
}
Output
Program
import java.io.*;
import java.util.*;
import java.time.LocalDate;
import java.time.Period;
class Person
{
int age;
double aadhar;
String surname,name,birthdate;
Date dob;
void ReadData()
{
Scanner sc=new Scanner(System.in);
System.out.println("Enter aadhar Number");
aadhar=sc.nextDouble();
System.out.println("Enter surname");
surname=sc.next();
System.out.println("Enter Name");
name=sc.next();
System.out.println("Enter Date of birth in YYYY-MM-DD format");
birthdate=sc.next();
LocalDate dob=LocalDate.parse(birthdate);
age=calculateAge(dob);
}
void DisplayData()
{
System.out.println("Aadhar Number: "+aadhar);
System.out.println("Student Surname: "+surname);
System.out.println("Student Name: "+name);
System.out.println("Date of Birth: "+birthdate);
System.out.println("Age: "+age);
}
public static int calculateAge(LocalDate dob)
{
LocalDate curDate = LocalDate.now();
if ((dob != null) && (curDate != null))
{
return Period.between(dob, curDate).getYears();
}
else
{
return 0;
}
}
}
class Student extends Person
{
int admno,year;
String cname,course;
void ReadData()
{
super.ReadData();
Scanner sc=new Scanner(System.in);
System.out.println("Enter admission Number");
admno=sc.nextInt();
System.out.println("Enter College name and course name");
cname=sc.next();
course=sc.next();
System.out.println("Enter year of study(1st/2nd/3rd)");
year=sc.nextInt();
}
void DisplayData()
{
super.DisplayData();
System.out.println("Admission Number: "+admno);
System.out.println("College Name: "+cname);
System.out.println("Course Name: "+course);
System.out.println("Year of Study: "+year);
}
}
class Inheritance
{
public static void main(String[] args)
{
Student s=new Student();
s.ReadData();
s.DisplayData();
}
}
Output
Program
import java.io.*;
interface Inter
{
final int a = 10;
void display();
}
class InterfaceEx implements Inter
{
public void display()
{
System.out.println("Example of Interface");
}
public static void main(String[] args)
{
InterfaceEx t = new InterfaceEx();
t.display();
System.out.println(a);
}
}
Output
15. Program to implement Multiple Inheritance
import java.io.*;
interface Father
{
final static double height=6.2;
void calculate();
}
interface Mother
{
final static double height=5.4;
void calculate();
}
class Child implements Father,Mother
{
public void calculate()
{
double height=(Father.height+Mother.height)/2;
System.out.println("Childs Height: "+height);
}
}
class MI
{
public static void main(String[] args)
{
Child c=new Child();
c.calculate();
}
}
Output
Comments
Post a Comment