Ruby的字符串与数组求最大值的相关问题讨论

b=[1,3,55,777,2,4,6,8,0]

b.max => 777
b.min => 0

# enum.max         -> obj
# enum.max { |a, b| block } -> obj
#a = %w(albatross dog horse)
#a.max          => "horse"
# a.max { |a, b| a.length <=> b.length } #=> "albatross"

d=%w(albatross dog horse ddd dasgfds)
d.max => "horse"

a = ["1", "3", "55", "777", "2", "4", "6", "8", "0"]
def max(first,*rest) 
 max=first 
 rest.each do |x|
  p "---#{x}---#{max}"
  max=x if x>max 
  p "---#{x}---#{max}"
  max 
end

"---3---1"
"---3---3"
"---55---3"
"---55---55"
"---777---55"
"---777---777"
"---2---777"
"---2---777"
"---4---777"
"---4---777"
"---6---777"
"---6---777"
"---8---777"
"---8---8"
"---0---8"
"---0---8"
 => "8"

"7" > "777" => false
"6" > "777" => false
"9" > "777" => true
"10" > "777" => false
"11" > "777" => false
"70" > "777" => false
"80" > "777" => true

ary.sort          -> new_ary
ary.sort { |a, b| block } -> new_ary
enum.sort_by { |obj| block }  -> array
enum.sort_by          -> an_enumerator

h=['1','3','13','10','7']
 A. p h.sort
 B. p h.sort{|a,b| a.to_i <=> b.to_i}
 C. p h.sort_by{|x| x.to_i}

A. ["1", "10", "13", "3", "7"] 
B. ["1", "3", "7", "10", "13"] 
C. ["1", "3", "7", "10", "13"]