Ruby inject with initial being a hash

Question

Can any one tell me why the following:

[\'a\', \'b\'].inject({}) {|m,e| m[e] = e }

throws the error:

IndexError: string no         


        

Answer 1

Your block needs to return the accumulating hash:

['a', 'b'].inject({}) {|m,e| m[e] = e; m }

Instead, it's returning the string 'a' after the first pass, which becomes m in the next pass and you end up calling the string's []= method.