This shot will discuss how to make a butterfly pattern in C++ using stars, i.e., `*`. 

Before moving on, it is advised to go through these articles so that it becomes easy to understand the logic to generate a butterfly pattern.

1. [Generate a half pyramid pattern with stars in C++
](https://www.educative.io/answers/generate-a-half-pyramid-pattern-with-stars-in-cpp)

2. [Generate an inverted half pyramid pattern with stars in C++
](https://www.educative.io/answers/generate-an-inverted-half-pyramid-pattern-with-stars-in-cpp)

# Methodology

To create this image, we will use nested loops. A **nested loop** is a loop that contains an *inner* loop inside an *outer* loop.

Let’s look at the below image to understand this better.

We will use nested `for` loops to generate the above illustration.

The first `for` loop will generate the *left half of the butterfly* pattern, while the second `for` loop will generate the *right half of the butterfly* pattern. 

The butterfly is made with two *rotated solid half pyramids*, one on the left and one on the right.

# Code

Let’s look at the below code implementation to understand this better.

#include <iostream>
using namespace std;

int main() {
  int number;
  cin >> number;

  for (int i = 0; i < number; i++) {
    for (int j = 0; j < (2*number); j++) {
      if (i >= j)
        cout << "*";
      else
        cout << " ";
      if (i >= (2*number-1)-j)
        cout << "*";
      else
        cout << " ";
    }
    cout << endl;
  }

  for (int i = 0; i < number; i++) {
    for (int j = 0; j < (2*number); j++) {
      if(i + j <= number-1)
        cout << "*";
      else 
        cout << " ";
      if((i+number) <= j)
        cout << "*";
      else
        cout << " ";
    }
    cout << endl;
  }
  return 0;
}

# Explanation

>To execute the above code, enter any number as input.

* In line 5: we initialize the variable `number`.

* In line 6: we take the input as a `number` using `cin >>`.

* From lines 8 to 19: the nested `for` loops takes iterators `i` and `j` to iterate through the given `number`. The `if-else` statement prints `*` to generate the *left half of the butterfly*.

* From lines 22 to 35: similar to above nested `for` loops, this loop uses `*` to `print` the *right half of the butterfly*.

In this way, we can generate a butterfly pattern using stars in C++.

> Note: We can also use *numbers*, *alphabets*, or any *other characters* to generate this pattern.

How to generate a butterfly pattern using stars in C++

Use nested loops to create left and right halves of a butterfly pattern with stars.