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Benx Shen's personal annotations on this page

Benxshen bookmarked on 2009-10-24

The function also returns a single value with the return keyword. Technically this isn't necessary -- the value of the last line executed in the function is used as the return value -- but more often than not using return explicitly makes things clearer.
Functions interact with blocks through the yield. Every time the function invokes yield control passes to the block. It only comes back to the function when the block finishes. Here's a simple example:
```
# Script block2.rb

def simpleFunction
  yield 
  yield
end

simpleFunction { puts "Hello!" }
```
```
$ block2.rb
Hello!
Hello!
```
The simpleFunction simply yields to the block twice -- so the block is run twice and we get two times the output. Here's an example where the function passes a parameter to the block:
```
# Script block1.rb

def animals
  yield "Tiger"
  yield "Giraffe"
end

animals { |x| puts "Hello, #{x}" }
```
```
$ block1.rb
Hello, Tiger
Hello, Giraffe
```

This link has been bookmarked by 1 people . It was first bookmarked on 24 Oct 2009, by Benx Shen.