Programming Point

The if statement in C language is used to perform operation on the basis of condition.
By using if-else statement, you can perform operation either condition is true or false.
There are many ways to use if statement in C language:
1.If statement
2.If-else statement
3.If else-if ladder
4.Nested if

The single if statement in C language is used to execute the code if condition is true.
The syntax of if statement is given below:
if(condition)
{
//code to be executed
}

#include<stdio.h>
#include<conio.h>
void main()
{
int number=0;
clrscr();

printf("enter a number:");
scanf("%d",&number);

if(number%2==0)
{
printf("%d is even number",number);
}
getch();
}
Output
enter a number:4
4 is even number

The if-else statement in C language is used to execute the code if condition is true or false.
The syntax of if-else statement is given below:
if(condition)
{
//code to be executed if condition is true
}
else
{
//code to be executed if condition is false
}

Let's see the simple example of even and odd number using if-else statement in C language.

#include<stdio.h>
#include<conio.h>
void main()
{
int number=0;
clrscr();

printf("enter a number:");
scanf("%d",&number);

if(number%2==0)
{
printf("%d is even number",number);
}
else
{
printf("%d is odd number",number);
}
getch();
}
Output
enter a number:4
4 is even number
enter a number:5
5 is odd number

The if else-if statement is used to execute one code from multiple conditions.
The syntax of if else-if statement is given below:

if(condition1)
{
//code to be executed if condition1 is true
}
else if(condition2)
{
//code to be executed if condition2 is true
}
else if(condition3)
{
//code to be executed if condition3 is true
}
else
{
//code to be executed if all the conditions are false
}

The example of if-else-if statement in C language is given below.

#include<stdio.h>
#include<conio.h>
void main()
{
int number=0;
clrscr();

printf("enter a number:");
scanf("%d",&number);

if(number==10)
{
printf("number is equals to 10");
}
else if(number==50)
{
printf("number is equal to 50");
}
else if(number==100)
{
printf("number is equal to 100");
}
else
{
printf("number is not equal to 10, 50 or 100");
}
getch();
}
Output
enter a number:4
number is not equal to 10, 50 or 100
enter a number:50
number is equal to 50