"functions are first class values" what does this exactly mean?

Question

Could somebody clearly explain it with some good example. I came across this statement in Scala, when explaining about the functional programming.

Accepted Answer

It means that functions can be passed around the same way as integers, sequences, etc.

An example (although not Scala):

```
>>> def add2(x):
...   return x + 2
... 
>>> map(add2, [1, 2, 3])
[3, 4, 5]
```

Solution