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# Set Operations On Sequences

## Preliminaries

`import scala.collection.mutable.ArrayBuffer`

## Create Two Array Sequences

```
// Create two arrays of ages
val student_ages = ArrayBuffer(42,25,28,38,58,63,23,458,2569,584,25,25)
val teacher_ages = ArrayBuffer(23,25,25,38,58,32,23,23,125,23,23,21,26)
```

## Concatenate Two Sequences

```
// Join two sequences end to end
student_ages ++ teacher_ages
```

```
ArrayBuffer(42, 25, 28, 38, 58, 63, 23, 458, 2569, 584, 25, 25, 23, 25, 25, 38, 58, 32, 23, 23, 125, 23, 23, 21, 26)
```

## Intersection (Shared Elements) Of Two Sequences

```
// Create the interaction of two sequences
teacher_ages.intersect(student_ages)
```

```
ArrayBuffer(23, 25, 25, 38, 58)
```

## Union (All Elements) Of Two Sequences

```
// Create the union of two sequences
teacher_ages.union(student_ages)
```

```
ArrayBuffer(23, 25, 25, 38, 58, 32, 23, 23, 125, 23, 23, 21, 26, 42, 25, 28, 38, 58, 63, 23, 458, 2569, 584, 25, 25)
```

## Unique Elements In Union Of Two Sequences

```
// Create the union of two sequences then keep only the unique values
teacher_ages.union(student_ages).distinct
```

```
ArrayBuffer(23, 25, 38, 58, 32, 125, 21, 26, 42, 28, 63, 458, 2569, 584)
```

## Relative Complement Of Two Sequences

```
// Elements in student_ages but not in teacher_ages
student_ages diff teacher_ages
```

```
ArrayBuffer(42, 28, 63, 458, 2569, 584, 25)
```

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