What does the |variable| syntax mean? [duplicate]

Answer 1

They are part of the syntax for defining a block. The way I like to explain it is that the pipes look like a slide and those variables inside the pipes "slide" down into the block of code below them.

Essentially the variables in the pipes are available to the block. In the case of iteration the variable would represent an element in whatever you are iterating over.

Answer 2

The pipe characters delimit the parameter list of a block definition just like parentheses delimit the parameter list of a method definition. So, in this code snippet:

def foo(bar, baz) end

some_method_that_takes_a_block do |bar, baz| end

The parentheses and the pipes have the exact same purpose.

Answer 3

it's like a foreach, so profile will be a different value in each of the functions calls, one function call per element in get_all.

see this:

my_array = [:uno, :dos, :tres]
my_array.each do |item| 
    puts item
end

Answer 4

I'll use this example to try to explain the concept to you.

friends = ["James", "Bob", "Frank"]
friends.each { |friend| puts friend }

James
Bob
Frank

So here, we have an array of our friends: James, Bob, and Frank.

In order to iterate over them, we call the #each method on the array. The method will start with the first item in my array and call the block on it.

Essentially, the item that I'm currently iterating over is passed to the variable inside of the two pipe characters. You can call it |buddy| and change the block to { |buddy| puts buddy } and it would still do the same thing.