There are several ways to compute the length of an array in C++.

# Using `sizeof()`

One way​ to find the length of an array is to divide the size of the array by the size of each element (in bytes).

The built-in **`sizeof()` operator** is used for this purpose (shown in the code snippet below):

#include <iostream>
using namespace std;

int main() {
  int arr[] = {10,20,30,40,50,60};
  int arrSize = sizeof(arr)/sizeof(arr[0]);
  cout << "The size of the array is: " << arrSize;
  return 0;
}

# Using pointer arithmetic

Since we have a pointer at the start of the array, the length of the​ array can be calculated if we manage to find out the address where the array ends. This is done as follows:

```c++
int arrSize = *(&arr + 1) - arr;
```
Let's break down the above line of code:
- **`(&arr + 1)`** points to the memory address right after the end of the array.
- **`*(&arr + 1)`** simply casts the above address to an `int *`.
- Subtracting the address of the start of the array, from the address of the end of the array,​ gives the length of the array.

Here's how it's implemented:

#include <iostream>
using namespace std;

int main() {
  int arr[] = {10,20,30,40,50,60};
  int arrSize = *(&arr + 1) - arr;
  cout << "The length of the array is: " << arrSize;
  return 0;
}

How to find the length of an ​array in C++

There are several ways to compute the length of an array in C++. 

How to find the length of an ​array in C++

Using sizeof()

Using pointer arithmetic

How to find the length of an array in C++

Using `sizeof()`