Syntax for a for loop in ruby

Question

How do I do this type of for loop in Ruby?

for(int i=0; i

Answer 1

If you don't need to access your array, (just a simple for loop) you can use upto or each :

Upto:

1.9.3p392 :030 > 2.upto(4) {|i| puts i}
2
3
4
 => 2 

Each:

1.9.3p392 :031 > (2..4).each {|i| puts i}
2
3
4
 => 2..4 

Answer 2

array.each do |element|
  element.do_stuff
end

or

for element in array do
  element.do_stuff
end

If you need index, you can use this:

array.each_with_index do |element,index|
  element.do_stuff(index)
end

Answer 3

Ruby's enumeration loop syntax is different:

collection.each do |item|
...
end

This reads as "a call to the 'each' method of the array object instance 'collection' that takes block with 'blockargument' as argument". The block syntax in Ruby is 'do ... end' or '{ ... }' for single line statements.

The block argument '|item|' is optional but if provided, the first argument automatically represents the looped enumerated item.

Answer 4

The equivalence would be

for i in (0...array.size)
end

or

(0...array.size).each do |i|
end

or

i = 0
while i < array.size do
   array[i]
   i = i + 1 # where you may freely set i to any value
end

Answer 5

limit = array.length;
for counter in 0..limit
 --- make some actions ---
end

---

the other way to do that is the following

3.times do |n|
  puts n;
end

thats will print 0, 1, 2, so could be used like array iterator also

Think that variant better fit to the author's needs

Answer 6

array.each_index do |i|
  ...
end

It's not very Rubyish, but it's the best way to do the for loop from question in Ruby