this operator in java

code:


class cl {

public double a,b;

// A normal parametrized constructor
public cl(int a,int b) {
this.a = a;
this.b = b;
}

// copy constructor
cl(cl c) {
System.out.println("Copy constructor called");
a = c.a;
b = c.b;
}



void f()
{
    System.out.println(a+" "+b);
}
}

public class Main {

public static void main(String[] args) {
cl c1 = new cl(10, 15);

// Following involves a copy constructor call
cl c2 = new cl(c1);
c1.f();
c2.f();
System.out.println("xxxxxxxxxxxxx");
c1.a=5;
c1.f();
c2.f();

// Note that following doesn't involve a copy constructor call as
// non-primitive variables are just references.
cl c3 = c2;
System.out.println("xxxxxxxxxxxxx");
c3.f();
c2.f();
c1.f();
System.out.println("xxxxxxxxxxxxx");
c2.a=6;
c1.f();
c2.f();
c3.f();
System.out.println("xxxxxxxxxxxxx");
        c3.a=7;
c1.f();
c2.f();
c3.f();
System.out.println("xxxxxxxxxxxxx");
        c1.a=8;
c1.f();
c2.f();
c3.f();

}
}


output::

$javac Main.java
$java -Xmx128M -Xms16M Main
Copy constructor called
10.0 15.0
10.0 15.0
xxxxxxxxxxxxx
5.0 15.0
10.0 15.0
xxxxxxxxxxxxx
10.0 15.0
10.0 15.0
5.0 15.0
xxxxxxxxxxxxx
5.0 15.0
6.0 15.0
6.0 15.0
xxxxxxxxxxxxx
5.0 15.0
7.0 15.0
7.0 15.0
xxxxxxxxxxxxx
8.0 15.0
7.0 15.0
7.0 15.0

roots of equation in java

roots of equation                                    edited by diya

equals() in java

equals() in java                                                                            edited by diya

import java.util.Scanner;

class p19

{

public static void main(String args[])

{

Scanner n=new Scanner(System.in);

System.out.println("Enter a string");

String s1=n.nextLine();

System.out.println("Enter a string");

String s2=n.nextLine();

System.out.println(s1.equals(s2));

}

}

D:\>javac p19.java

D:\>java p19

Enter a string

diya

Enter a string

diya

true

D:\>java p19

Enter a string

dil

Enter a string

diya

false

D:\>

compareTo()

compareTo()                                                         edited by diya

import java.util.Scanner;

class p19

{

public static void main(String args[])

{

Scanner n=new Scanner(System.in);

System.out.println("Enter a string");

String s1=n.nextLine();

System.out.println("Enter a string");

String s2=n.nextLine();

int a=s1.compareTo(s2);

System.out.println("after comparesion");

System.out.println(a);

}

}

D:\>javac p19.java

D:\>java p19

Enter a string

diya

Enter a string

sayan

after comparesion

-15

D:\>

string concatenation

string concatenation                                                                                edited by diya

import java.util.Scanner;

class p19

{

public static void main(String args[])

{

Scanner n=new Scanner(System.in);

System.out.println("Enter a string");

String s1=n.nextLine();

System.out.println("Enter a string");

String s2=n.nextLine();

s1=s1.concat(s2);

System.out.println("after concatenation");

System.out.println(s1);

}

}

D:\>javac p19.java

D:\>java p19

Enter a string

dil

Enter a string

diya

after concatenation

dildiya

D:\>

vowel counting

vowel counting                                                                       edited by diya

import java.util.Scanner;

class p19

{

public static void main(String args[])

{

Scanner n=new Scanner(System.in);

int v=0;

System.out.println("enter a string");

String s=n.nextLine();

for(int i=0;i<s.length();i++)

{

char ch=s.charAt(i);

if(ch=='a'||ch=='e'||ch=='i'||ch=='o'||ch=='u')

{

v++;

}

}

System.out.println("total vowel="+v);

}

}

D:\>java p19

enter a string

kolkata

total vowel=3

D:\>

length of a string

//length of a string                                                                    edited by diya

class p19

{

public static void main(String args[])

{

String s="rittik";

System.out.println("length="+s.length());

for(int i=0;i<s.length();i++)

{

    char ch=s.charAt(i);

    System.out.println(ch);

}

}

}

D:\>java p19

length=6

r

i

t

t

i

k

D:\>

list of functions String class

SL NO	CLASS    NAME	FUNCTION     NAME	PROGRAM     NAME	LINK
1.	String		string initialization in java	clickhere
2.	String		string concate using + in java	click here
3.	String	String concat(String str)	string concat using function	clickhere
4.	String		string compare using== in java	click here
5.	String	boolean equals(string object)	string compare using equals() in java	click here
6.	String	static String equalsIgnoreCase(String another)	string compare equalsignorecase()  in java	clickhere
7.	String	int compareTo(Object ob)	compare string lexicographically	click here
8.	String	int length()	string length() in java	click here
9.	String	char charAt(int index)	string charAt() in java example	click here
10.	String		vowel count in java	click here
11.	String	String trim()	string trim() in java	click here
12.	String	String replace(CharSequence old, CharSequence new)	string replace() in java	click here
13.	String	static String join(delimiter,delimeter1,....)	string join() in java example	click here
14.	String	boolean isEmpty()	string isempty() in java	clickhere
15.	String	boolean contains(CharSequence s)	string contains() in java	click here
16.	String		string pattern in java	click here
17.	String	int indexOf(int ch)	string indexOf()	click here
18.	String	int indexOf(int ch, int fromIndex)	string indexOf()	click here
19.	String	int indexOf(String substring)	string indexOf()	click here
20.	String	int indexOf(String substring, int fromIndex)	string indexOf()	click here
21.	String	int lastIndexOf(int ch)	lastIndexOf() in java	click here
22.	String	int lastIndexOf(int ch, int fromIndex)	lastIndexOf() in java	click here
23.	String	int lastIndexOf(String substring)	lastIndexOf() in java	click here
24.	String	int lastIndexOf(String substring, int fromIndex)	lastIndexOf() in java	click here
25.	String	String substring(int beginIndex)	substring() in java	click here
26.	String	String substring(int beginIndex, int endIndex)	substring() in java	click here
27.	String	String toUpperCase() String toLowerCase()	toUpperCase(),toLowerCase() in java	click here
28.	String		string pallindrome checking in java	click here

1. length of a string. -  link

2. count total vowels in a string. - link
3. concatenation of two strings. - link
4. compareTo () - link
5. equals() - link

SUM AND AVERAGE OF N ELEMENTS IN DYNAMIC ARRAY IN CORE JAVA

Sum and average of n numbers using dynamically array                           EDITED BY SAYANI

Code:

import java.util.Scanner;

class arr

{

int a[],length;

void iplength(int x)

{

length=x;

}

void iparray()

{

a=new int [length];

Scanner j=new Scanner(System.in);

for(int i=0;i<length;i++)

{

a[i]=j.nextInt();

}

}

void op()

{

 int sum=0;

for(int i=0;i<length;i++)

{

sum=sum+a[i];

}

System.out.println("Sum="+sum);

double avg=(double)sum/(double)length;

System.out.println("Average="+ avg);

}

}

class arr1

                {

                                public static void main(String args[])

                                {

                                                arrob=new arr();

                                                ob.iplength(5);

                                                ob.iparray();

                                                ob.op();

                                }

                }

Output:E:\>javac arr1.java

E:\>java arr1

2

4

5

7

9

Sum=27

Average=5.4

E:\>

CONSTRUCTOR OVERLOADING

CONSTRUCTOR OVERLOADING WITHOUT PARAMETER, SINGLE PARAMETER, MULTIPLE PARAMETER

import java.util.Scanner;

class day

                {

                int a;

               

                day()

                {

                System.out.println("Sunday");

                }

                day(int x)

                {

                System.out.println("Monday");

                }

                day(int x,int y)

                {

                System.out.println("Friday");

                }

                }

class day1

                {

                public static void main(String args[])

                {

                day ob1=new day();

                day ob2=new day(5);

                day ob3=new day(7,9);

                }

                }

Output:

E:\>javac day1.java

E:\>java day1

Sunday

Monday

Friday

E:\>