Ruby编程之数组索引、数组拷贝与克隆

arr = ['h','e','l','l','o',' ','w','o','r','l','d']
print( arr[0,5] ) #=> hello (or) ["h", "e", "l", "l", "o"]
print( arr[-5,5 ] ) #=> world (or) ["w", "o", "r", "l", "d"]
print( arr[0..4] ) #=> hello (or) ["h", "e", "l", "l", "o"]
print( arr[-5..-1] ) #=> world (or) ["w", "o", "r", "l", "d"]
p( arr[0,5] ) #=> ["h", "e", "l", "l", "o"]
p( arr[0..4] ) #=> ["h", "e", "l", "l", "o"]

["h", "e", "l", "l", "o"]["w", "o", "r", "l", "d"]["h", "e", "l", "l", "o"]["w", "o", "r", "l", "d"]["h", "e", "l", "l", "o"]
["h", "e", "l", "l", "o"]

arr = []
arr[0] = [0]
arr[1] = ["one"]
arr[3] = ["a", "b", "c"]
puts(arr[0])
puts(arr[1])
puts(arr[3])
arr2 = ['h','e','l','l','o',' ','w','o','r','l','d']
arr2[0] = 'H'
arr2[2,2] = 'L', 'L'
arr2[4..6] = 'O','-','W'
arr2[-4,4] = 'a','l','d','o'
puts(arr2[0])
puts(arr2[2,2])
puts(arr2[4..6])
puts(arr2[-4,4])

0
one
a
b
c
H
L
L
O
-
W
a
l
d
o

arr1=['h','e','l','l','o',' ','w','o','r','l','d']
arr2=arr1 # arr2 is now the same as arr1.
# Change arr1 and arr2 changes too!
arr3=arr1.clone
# arr3 is a copy of arr1.
# Change arr3 and arr2 is unaffected
puts(arr1)
puts(arr2)
puts(arr3)

h
e
l
l
o

w
o
r
l
d
h
e
l
l
o

w
o
r
l
d
h
e
l
l
o

w
o
r
l
d

开发环境:Rubymine

The book of Ruby----A hands-on guide for the Adventurous---[美]Huw Collingbourne---no starch press