Decision making structures require that the programmer specifies one or more conditions to be evaluated or tested by the program, along with a statement or statements to be executed if the condition is determined to be true, and optionally, other statements to be executed if the condition is determined to be false.

We can better visualize the conditional by using the flowchart for this code,


if x == y:
    print('x and y are equal')
else:
    if x < y:
        print('x is less than y')
    else:
        print('x is greater than y')
 Visual description of conditionalThe outer conditional has two branches. The second branch contains another if statement, which has two branches of its own. Those two branches are both simple statements, although they could have been conditional statements as well.

Example of ‘if’

// Program to display a number if it is negative
#include <stdio.h>
int main()
{
	int number;
	printf("Enter an integer: ");
	scanf("%d", &number);
	// true if number is less than 0
	if (number < 0)
	{
		printf("You entered %d.\n", number);
	}
	printf("The if statement is easy.");
	return 0;
}