if else statement in C language 

In if else statement, there is only one condition. If  condition is true, one set of statements will be executed otherwise another set of statements will be executed

Syntax of if else statement is:

if(Test)
{
  Block1;
}
else
{
  Block2;
}

Test is any conditional expression If  it is true, then Block1 of statements gets executed otherwise Block2 of statements gets executed.

#include<stdio.h>
int main()
{
int a;
printf("\nEnter a number:=");
scanf("%d",&a);
if(a>0)
  printf("\nnumber is positive");
else
  printf("\nNumber is not positive");
}

Enter a number:= 7
Number is not positive

In the above program, a has been entered 7.  Condition a>0 is true so printf(“Number is  positive”) will be executed