调用所有数组元素的函数，而不将item作为参数传递

Question

In javascript I can do this:

var show = function(w) {
  alert(w);
};

var words =  ['a', 'b', 'c'];
words.forEach(show);

Note that I don't need to pass the array item as a parameter.

Is there a way to the same in ruby?

Like:

def show(w)
  puts w
end

words = ['a', 'b', 'c']
words.each(show)

PS: I know that I can do it by doing: words.each { |w| show(w) } words.each { |w| show(w) } . The question is if I can do it like in javascript, without passing the item as a parameter.

Answer 1

Sure, you do it by passing the method, just like you do in ECMAScript:

words.each(&method(:show))

Note that this is the way to make your Ruby example work. However, a Ruby method is not really the closest analogue to an ECMAScript function in Ruby. A Proc would actually be a closer match:

show = -> w { puts w }

words.each(&show)

This actually reads very close to the ECMAScript 6 version:

const show = w => alert(w);

words.forEach(show);