# Collection - (Tuple|Vector|Row)

### Table of Contents

## About

A tuple is:

- a finite list of elements (fields) - It can only contain a specific number of elements.
- ordered by position
- that may have different types.
- and still be completely typesafe.

You can see tuple:

Example with a tuple assignement.

`(x,y,z) = (2,4,'Bar')`

would result in the following tuple:

<math> \begin{array}{rrr} 0 & \mapsto & x & \mapsto & 2\\ 1 & \mapsto & y & \mapsto & 4\\ 2 & \mapsto & z & \mapsto & Bar\\ \end{array} </math>

A Tuple has a schema defining each field

The term tuple comes from the set theory.

In set theory, an (ordered) n-tuple is a sequence (or ordered list) of n elements, where n is a non-negative integer.

Tuples are often used to describe other mathematical objects, such as vector

In a relational database, a tuple is called a row.

## Size

Size | Name | Signature |
---|---|---|

1 | Unit | A |

2 | Pair | A, B |

3 | Triplet | A, B, C |

4 | Quartet | A, B, C, D |

5 | Quintet | A, B, C, D, E |

6 | Sextet | A, B, C, D, E, F |

7 | Septet | A, B, C, D, E, F, G |

8 | Octet | A, B, C, D, E, F, G, H |

9 | Ennead | A, B, C, D, E, F, G, H, I |

10 | Decade | A, B, C, D, E, F, G, H, I, J |

See also Function - Arity

## Implementation

- Apache Commons tuple (of degree 1 until 3, ie only 1 to 3 columns)