## Set operations on ruby arrays

Ruby provides some very interesting set operations on arrays.

given the two arrays A and B wich look like this

```
A = ["A", "B", "C", "D"]
B = ["C", "D", "E"]
```

There are three set operations we can use that union, intersection and difference.

## Union

```
A | B
```

contains all elements from both sets without doublicates. So this results in ["A", "B", "C", "D", "E"]

## Difference

```
A - B
```

contains all elements from set A that are not in set B. So this results in ["A", "B"]

## Intersection

```
A & B
```

contains all elements that are in set A and in set B. So this results in ["C", "D"]

## See also:

ruby rhyme generator

Curling Animation II

Blinking Logfile Map

Curling Recursion

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