C if else Statement

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:

• If statement
• If-else statement
• If else-if ladder
• Nested if

If Statement

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(expression){  

//code to be executed  

Flowchart of if statement in C

 

Let's see a simple example of c language if statement.

#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

enter a number:5

If-else Statement

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(expression){  
//code to be executed if condition is true  
}else{  
//code to be executed if condition is false  
}  

Flowchart of if-else statement in C

 

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

If else-if ladder Statement

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  
}  

Flowchart of else-if ladder statement in C

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