In this shot, we will learn how to use the **`ratio_equal()` function**. This template alias is used to check the equality between the two ratios and gives the boolean value as a result i.e., either `true` or `false`. The comparison is done between the simplest form of the two ratios by the `ratio_equal()` method.
> The `ratio_equal()` function is available in the `<ratio>` header file in C++.

#   
#  What is a ratio?
A **ratio** is a representation of a fraction in which the numerator and denominator are differentiated by the colon (:) symbol. The numerator and denominator can be of `float` data type.

Let’s understand with the help of some examples. Suppose we have the following ratios:
- 1 : 5  
- 5 : 25

The result of the `ratio_equal()` function on comparison for equality of these two ratios gives the result as `true`. 

Let’s explore how the equality check took place.

- The ratios 1 : 5 and 5 : 25 can be represented as $\frac{1}{5}$ and $\frac{5}{25}$ in fractional form respectively.

- The ratio $\frac{1}{5}$ is itself a simplified form.
$\frac{5}{25}$ on simplification gives $\frac{1}{5}$.

- Now, the simplified fractions $\frac{1}{5}$ and $\frac{1}{5}$  are compared for equality. So, the final result is true.


#   
#  Parameters
The `ratio_equal()` method takes the  parameters below:
* `Ratio1`: A `ratio` object which is to be compared for equality with the other ratio object.
* `Ratio2`: Another `ratio` object which gets compared for equality with the previous ratio object.

##  
## Return value
It returns the Boolean result after comparison for equality.
If the ratio objects are equal then it returns `true`.
If the ratio objects are not equal then it returns `false`.

##  
## Code
Let’s have a look at the code.

#include <iostream>
#include <ratio>
using namespace std;

int main()
{
  typedef ratio<1, 3> ratio1;
  typedef ratio<5, 2> ratio2;
  
  if (ratio_equal<ratio1, ratio2>::value)
    cout<<"Ratio 1 and Ratio 2 are equal";
  else
    cout<<"Ratio 1 and Ratio 2 aren't equal";
  
  return 0;
}


## Explanation
* In lines 1 and 2 we imported the required header files.
* In line 5 we made a `main()` function.

* From lines 7 and 8 we declared two ratios.
* In line 10 we performed the comparison between the two declared ratios by using the `ratio_equal()` function as a condition inside the `if` statement. If the two ratio objects are equal then the if statement gets executed and displays the message regarding the result.
* In line 12, if the condition doesn’t satisfy i.e., the two ratio objects are not equal, then the statement gets executed and displays the message regarding the result.

In this way, we can use the `ratio_equal()` function to check whether the two ratios are equal or not.



How to use the ratio_equal() function in C++

The `ratio_equal()` function in C++ checks the equality of two ratios, returning true if they are equal and false otherwise.