The **`set.first` function** in Dart is used to get the reference of the first element in the set.

The image below shows the visual representation of the `set.first` function.

---
>In Dart, a **`set`** is a particular instance of a list in which all of the inputs are unique.

> `dart:core` is required in order to use this function.
---

>If there are duplicates, then the set will only keep the first instance. For instance,
`{'Tom','Alsvin','Eddie','Tom'}` will result in `{'Tom','Alsvin','Eddie'}`.

#   
## Syntax

```dart
element set_name.first
// where the set_name is the name of the set.
```
## Parameter

This function does not require a parameter.

## Return value
The `set.first` function returns the reference to the set's first element.
- `set.first` does not remove that element from the set.

- If the set is `empty`, then the function throws an `error`.

## Code
The code below shows how to use the `set.first` function in Dart.

import 'dart:convert';
import 'dart:core';
void main() {
  Set<String> set_1 = {'Tom','Alsvin','Eddie'}; 
  //set containing unique value
  print("set_1 elements: ${set_1}");
  print("set_1 first element: ${set_1.first}");

  Set<String> set_2 = {'Tom','Alsvin','Eddie','Tom'}; 
  //set containing non-unique value
  print("set_2 elements: ${set_2}");
  print("set_2 first element: ${set_2.first}");

}

What is the set.first method in Dart?

The set.first function in Dart returns the first element in a set, but throws an error if empty.