Sunday 3 March 2013

07:57 -

Explain all the if … else statements in C++ with a small code for each.


There are tow types of if….else statements in C++ which are explained below.

Simple if….else statement
Syntax: if(expression or condition)
          { statement 1;
             statement 2;
          }
          else
          { statement 3;
             statement 4;
          }

The expression or condition is any expression built using relation operators which either yields true or false condition. If no relational operator are used for comparison, then the expression will be evaluated and zero is taken as false and non zero value is taken as true.
If the condition is true, statement1 and statement2 is executed otherwise statement3 and statement4 is executed. Else part is optional. If there is no else part, then the next statement after the if statement is executed, if the condition is false.
Example: Find even odd numbers.
//evenodd.cpp
#include<iostream.h>
#include<conio.h>
void main()
{
int num;
cout<<”Please enter a number”<< endl;
cin>>num;
if((num%2)==0)
{
count<<num<<”is a even number”;
                   }
else
{
cout<<num<<”is a odd number”;
}
getch();
}

Nested If statement
If statement can be nested in another if statement to check multiple condition.
Syntax:
if(condtion1)
{ if(condtion2)
          { statement1;
          statement2;
          }
else if(condtion3)
          { statement3;
          }
}

Example: Fine large number.
//Large.cpp
#include<iostream.h>
void main()
{
          int a,b,c;
cout<<”Please enter three numbers.”;
cin>>a>>b>>c;
if((a>b) && (b>c))
          count<<a<<”is the largest number”;
else if((b>a) && (b>c))
          count<<b<<”is the largest number”;
else if((c>a) && (c>b))
          count<<c<<”is the largest number”;
}