Hi! 2009/1/8 Jun Young Kim <jykim / altibase.com>: > what's the definition of '*'? > is this pointer? It's called "splat operator". You can use it to "explode" your array elements or join some variables on an array. Note the difference: irb(main):001:0> a = [1,2]; b = [3,4] => [3, 4] irb(main):002:0> a.push(b) => [1, 2, [3, 4]] irb(main):003:0> a.push(*b) => [1, 2, [3, 4], 3, 4] And now: irb(main):004:0> def test(*args) irb(main):005:1> p args irb(main):006:1> end => nil irb(main):007:0> test(1) [1] => nil irb(main):008:0> test(1,2,3) [1, 2, 3] Regards,