C Program to Find the Largest Number Among Three Numbers (Using Nested if...else)

#include <stdio.h>

int main() {

  double n1, n2, n3;

  printf("Enter three numbers: ");
  scanf("%lf %lf %lf", &n1, &n2, &n3);

  // outer if statement
  if (n1 >= n2) {

    // inner if...else
    if (n1 >= n3)
      printf("%.2lf is the largest number.", n1);
    else
      printf("%.2lf is the largest number.", n3);
  }

  // outer else statement
  else {

    // inner if...else
    if (n2 >= n3)
      printf("%.2lf is the largest number.", n2);
    else
      printf("%.2lf is the largest number.", n3);
  }

  return 0;
}

Output

Enter three numbers: -4.5
3.9
5.6
5.60 is the largest number.