iterator - Ruby, error with brackets for code block -

so trying understand code blocks , iterators simple exercise, , ran issue using brackets don't understand.

i have 'my_times' method

class integer     def my_times         c = 0         until c == self             yield(c)        # passes 'c' code block             c += 1         end         self        # return self      end end 5.my_times {|i| puts "i'm on iteration #{i}"} 

which works fine, have 'my_each2' operates should

class array     def my_each2         size.my_times |i|     # <-- signifies code block correct? 'end' unnecessary?             yield self[i]         end         self     end end array.my_each2 {|e| puts "my2 block got handed #{e}"} 

from understanding 'do |i|' in "size.my_times |i|" code block (with no 'end'?) correct?
if so, why error trying put in {brackets} instead of using 'do'?

class array     def my_each3         size.my_times {|i| puts "i'm on iteration #{i}"} # <-- error here             yield(self[i])         end         self     end end array.my_each3 {|e| puts "my3 block got handed #{e}"} 

but using 'do' works

size.my_times |i| puts "i'm on iteration #{i}" 

the 'do |i|' in "size.my_times |i|" code block (with no 'end'?) correct?

no, not. do ... end code block.

if so, why error trying put in {brackets} instead of using 'do'?

since condition not satisfied, question trivially satisfied.