Nested if block in c

Nested if block:

• Defining if block inside another if block.
• Nested if condition evaluates only when outer condition is valid.

#include<stdio.h>
int main()
{
	if(1)
	{
		printf("Outer block statements \n");
		if(1)
		{
			printf("Inner block statements \n");
		}
	}
	return 0;
}

Nested if condition evaluates only when outer condition is valid.

#include<stdio.h>
int main()
{
	if(0)
	{
		printf("Outer block statements \n");
		if(1)
		{
			printf("Inner block statements \n");
		}
	}
	return 0;
}

Question:

• Read one number
• Check the number is divisible by 3 or 5 or both or none.

Example:

• 9 : Divisible by 3
• 15 : Divisible by 3 and 5
• 10 : Divisible by 5
• 13 : Not divisible by 3 or 5

#include<stdio.h>
int main()
{
	int n;
	printf("Enter a number : ");
	scanf("%d", &n);
	if(n%3==0)
	{
		if(n%5==0)
			printf("%d is divisible by 3 and 5 \n", n);
		else
			printf("%d is divisible by only 3\n", n);			
	}
	else
	{
		if(n%5==0)
			printf("%d is divisible by only 5\n", n);
		else
			printf("%d is not divisible by 3 or 5\n", n);
	}
	return 0;
}

Flow charts of Nested – if:

Flow-1:

Flow-2:

Biggest of 3 numbers using nested – if:

#include<stdio.h>
int main()
{
	int a, b, c;
	printf("Enter 3 numbers : ");
	scanf("%d%d%d", &a, &b, &c);
	
	if(a>b)
	{
		if(a>c)
			printf("a is big \n");
		else
			printf("c is big \n");	
	}
	else
	{
		if(b>c)
			printf("b is big \n");
		else
			printf("c is big \n");
	}
	return 0;
}

Leap year program:

• 4 divisible – leap year   (16, 44, 1660….)
• 400 divisible – leap year (800, 2000….)
• 100 divisible – not leap year (100, 200, 300, 500…)

#include<stdio.h>
int main()
{
	int year;
	printf("Enter Year name:");
	scanf("year: %d",&year);
	if(year%400==0 || (year%4==0 && year%100!=0))
	{
		printf("%d is leap year \n", year);
	}
	else
	{
		printf("%d is not a leap year \n",year);
	}
	return 0;
}

Note: try the above code using Nested-if