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Ruby Ruby Foundations Blocks Examples

Allen Wang
Allen Wang
3,439 Points
Posted by Allen Wang
Allen Wang
3,439 Points

What does the |a| do at the end of the how_many.times call?

I'm still having some difficulty understanding what is going on when there is a variable surrounded by || such as |a|, or when you have a block written as {|var| some operation on var}

1 Answer

Geoff Parsons
Geoff Parsons
11,679 Points

Effectively what you're doing when you pass a block to a method is defining a temporary anonymous (as in it has no name so you can't call it later on) function. The variables between the pipes ("|foo|") are the arguments that block takes. If we look at array#each we see that it will attempt to pass one argument to our block, item, so we should set up our block to accept a single parameter:

array.each do |item|
  puts item
end

Alternatively if we look at hash#each it will attempt to pass two variables to our block each time it is called, the key and that key's value.

hash.each do |key, value|
  puts "The value for #{key} is #{value}"
end

Hope that helps!