program to find prime number after giving number in C++

#include<iostream>
using namespace std;
int main ()
{
int i,j,num;
cout<<"Enter number:-";
cin>>num;
cout<<"next prime number:-";
for(i=num+1;i<2000;i++)
{
for(j=2;j<i;j++)
{
if(i%j==0)
{
//cout<<"no prime no:-";
break;
}

}
if(i==j||i==0)
{
cout<<"\t"<<i;
break;
}

return 0;

}
}

program to show prime number in C++.

//Prime number program in dev C++.

#include<iostream>

using namespace std;

int main()
{

int i,num;
cout<<"Enter number:-\n";
cin>>num;
if(num==1)
{
cout<<"1 is not a prime number and smallest prime number is 2";
}


for(i=2;i<num;i++)
{

if(num%i==0)
{

cout<<"number is not prime number";
break;

}

}
if(num==i)

{

cout<<"number is prime number";

}

return 0;

}

swap two number without using third variable in Dev c++

// program to swap two number without using third variable.

#include<iostream>
using namespace std;
int main()
{
int a,b;
cout<<"\n enter a:-";
cin>>a;
cout<<"\n enter b:-";
cin>>b;
a=a+b;
b=a-b;
a=a-b;
cout<<"\n after swapping: a:-"<<a<<"\n b"<<b;
return 0;

}

Swap two number in Turbo C+

//swap two numbers using three variables.

#include<iostream.h>
#include<conio.h>

void main()
{

int a,b,c;
clrscr();

cout<<"a=";
cin>>a;
cout<<"b=";
cin>>b;

c=a;//assigning value in c and c is temporary variable.

a=b;

b=c;//assigning value of c  in b.

cout<<"after swapping a:"<<a<<"\nb:"<<b;

getch();
}

program to check odd or even number in TurboC++

After doing this program you assure that, how to use if and else condition in programs.

//program to check even or odd no:

#include<iostream.h>
#include<conio.h>

void main()
{

int no;
clrscr();

cout<<"enter no:-";
cin>>no;

//checking if no is divisible by two or not.
if(no%2==0)

{

cout<<"\n even no";

}
else
{
cout<<"\n odd no";
}

getch();
}

Simple Multiplication table in C++

//Multiplication table in C++ and understand concept of for loop.

#include<iostream.h>
#include<conio.h>
void main()
{
int n,i;

cout<<"\n\t\ This program prints multiplication table:"<<"\n";
cout<<"Enter the value";
cin>>n;
for(i=1;i<=10;i++)
{
cout<<n;
cout<<"*";
cout<<i;
cout<<"=";
cout<<n*i;
cout<<"\n";

}
getch();
}

switch control in C and C++.

Switch condition

switch condition is used to print multiple value as  a code or showing different code in same programme.

syntax;

switch(expression)
{
case constant:
code;
break;
case constant:
code;
break;
case constant:
code;
break;
default:
code;
}

different cases are used to show different result.
constant are used to identify each code and it is not compulsory to have constant as a number or character we can take constant as a integer or character as we wish but we did not take constant as a float , like 1.2,1.3 etc.
it is also not compulsory to have constant on a sequence.
 we can use switch condition in place of nested-if statement, we can not use nested -if statement in longer programme because it is difficult to read programme.

Loops in programming languages.

Loops are used to repeat set of codes or a single code. There are three types of loops explained in below;

1)for loop

    This loop is very commonly used and syntax is very easy.

    syntax;

    for(var initialization; var condition; increament of variable)
    for example;

    for(i=0;i<=10;i++)
    {

      cout<<"";
      or
       printf("");

     }

2)while loop
  
   while loop is very simple and syntax is ;
    while(condition)
{
}
   
    while(x<=10)
     {
}

3)do-while loop
syntax;

do{
printf();
}
while();