## With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

No credit card required

# Higher order functions

Unix shells allow us to express computations as pipelines. Small programs called filters are piped together in unforeseen ways to ensure they work together. For example, refer to this code:

```~> seq 100 | paste -s -d '*' | bc
```

This is a very big number (obviously, as we just generated numbers from 1 to 100 and multiplied them together). There is looping involved, of course. We need to generate numbers from 1 to 100, connect them together via `paste`, and pass these on to `bc`. Now consider the following code:

```scala> val x = (1 to 10).toList
x: List[Int] = List(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)

scala> x.foldLeft(1) { (r,c) => r * c }
res2: Int = 3628800
```

Writing a for loop with a counter and iterating over the elements of the collection ...

## With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

No credit card required