If else statements in C is also used to control the program flow based on some condition, only the difference is: it's used to execute some statement code block if the expression is evaluated to true, otherwise executes else statement code block.
The basic format of if else statement is:
Syntax:
if(test_expression)
{
//execute your code
}
else
{
//execute your code
}
Figure - Flowchart of if-else Statement:
Example of a C Program to Demonstrate if-else Statement
Example:
#include<stdio.h>
void main()
{
int a, b;
printf("Please enter the value for a:");
scanf("%d", &a);
printf("\nPlease the value for b:");
scanf("%d", &b);
if (a > b) {
printf("\n a is greater");
} else {
printf("\n b is greater");
}
}
Program Output:
Example:
#include<stdio.h>
void main() {
int num;
printf("Enter the number:");
scanf("%d", &num);
/* check whether the number is negative number */
if (num < 0)
printf("The number is negative.");
else
printf("The number is positive.");
}
Program Output:
if-else Statements in C - Video Tutorial
To understand "C if-else Statements" in more depth, please watch
this video tutorial.