Ruby 数组方法

city=["北京","上海","天津","重庆"]
puts city
city=Array.new
city[0]="北京"
city[1]="上海"
city[2]="天津"
city[3]="重庆"
puts city

 

city=["北京","上海","天津","重庆"]
city[4]="香港"
puts "数组的长度为："+city.size.to_s
puts city
puts "第二个元素为："+city[1]
puts "最后一个元素为："+city[-1]

 

city=Array.new
city[2]="香港"
puts "数组的长度为："+city.size.to_s
puts city

 

str="深圳"
city_1=%W{北京 上海 天津 重庆 杭州 南京 #{str}}#使用%W{...}进行转换
puts city_1.size
puts city_1
city_2=%w{北京 上海 天津 重庆 杭州 南京 #{str}}#使用%w{...}进行转换
puts city_2

 

college=["北京大学","清华大学"]
college.unshift("浙江大学","复旦大学")    #向数组头部添加元素列表
college.push("南京大学","武汉大学")       #向数组尾部添加元素列表
college<<"南开大学"                       #向数组尾部添加一个元素
puts college.size.to_s
puts college
puts college.pop                          #删除并获取数组最后一个元素
puts college.shift                      #删除并获取数组第一个元素
puts college.size.to_s
puts college
puts college[2,3]                       #截取从索引2开始，长度为3的元素列表
puts college[2..3]                      #截取从索引2开始，到索引3的元素列表
puts college[2...3]                     #截取从索引2开始，到索引3(不包括)的元素列表

 

city_1=["北京","上海","天津"]
city_2=["重庆","香港"]
city_3=city_1+city_2
puts city_3.size.to_s
city_1.concat(city_2)
puts city_1.size.to_s

 

a=Array.new
p a

a=Array.new(5)
p a

a=Array.new(5,0)
p a
#lang=%W(a b c)
lang=%W{a b c}
p lang

h={"a"=>"b","c"=>"d"}
p h.to_a

s="ab cd efg"
a=s.split(" ")
p a
#p a.include?("ab")
#a.each_with_index do |b,i|
#  p b
#  p i
#end
#h = {:aaa => "bbb", :ccc => "ddd"}
#h.each_key do |key|
#  p h[key]
#end
#h.replace({:a => "b", :c => "d"})
#p h
#t = Time.now
#p t.strftime("%y")

a=[1,2,3,5,7,9]
b=[2,4,6,8,10]
#两数组相连
p (a+b)
#a数组中的元素减去b数组中与之相同的元素
p (a-b)
#（并集）除去两个数组中相同的元素
p (a|b)
#（交集）只有两个数组中都相同的元素
p (p&b)

a=[1,2,3,2]
a.delete(2)           #删除所有与X相同的元素
p a

a=[1,2,3,2]
a.delete_at(3)        #删除第n个元素
p a

a=[1,2,3,4,5,6,7,8,9,10]
a.slice!(1,5)         #删除数组中第几到第几个之间的所有数据
p a

a=[1,2,3,4,5,6,7]
a[1..6]=[4,5,6,7,8,9]   #a[n..m]方法可以选择改变数组
p a

a=[1,2,3,4,5,6,7,8,9]
a.each(){|s| p s}
a.each_with_index do |c,i|
   puts "#{i}  :  #{c}"
  puts (c+i).to_s
end

a=[[1,2],[2,3],[3,4],6]
p a.flatten

s = [ 1, 2, 3 ]           #=> [1, 2, 3]
t = [ 4, 5, 6, [7, 8] ]   #=> [4, 5, 6, [7, 8]]
a = [ s, t, 9, 10 ]       #=> [[1, 2, 3], [4, 5, 6, [7, 8]], 9, 10]
puts   a.flatten                 #=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
a = [ 1, 2, [3, [4, 5] ] ]
puts a.flatten(1)              #=> [1, 2, 3, [4, 5]]
puts a.flatten                #=> [1, 2, 3, 4, 5]

a=[1,1,2,2,3,3]
p a.uniq                      #去掉重复的元素

arr=[9,8,7,1,2,5,3]
p arr.sort                    #=> [1, 2, 3, 5, 7, 8, 9]
p arr                         #=> [9, 8, 7, 1, 2, 5, 3]
p arr.sort!                   #=> [1, 2, 3, 5, 7, 8, 9]
p arr                         #=> [1, 2, 3, 5, 7, 8, 9]
p arr.sort{|a,b| b<=>a}

 

 

[]
[nil, nil, nil, nil, nil]
[0, 0, 0, 0, 0]
["a", "b", "c"]
[["c", "d"], ["a", "b"]]
["ab", "cd", "efg"]
[1, 2, 3, 5, 7, 9, 2, 4, 6, 8, 10]
[1, 3, 5, 7, 9]
[1, 2, 3, 5, 7, 9, 4, 6, 8, 10]
false
[1, 3]
[1, 2, 3]
[1, 7, 8, 9, 10]
[1, 4, 5, 6, 7, 8, 9]
1
2
3
4
5
6
7
8
9
0  :  1
1
1  :  2
3
2  :  3
5
3  :  4
7
4  :  5
9
5  :  6
11
6  :  7
13
7  :  8
15
8  :  9
17
[1, 2, 2, 3, 3, 4, 6]
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
1
2
3
4
5
[1, 2, 3]
[1, 2, 3, 5, 7, 8, 9]
[9, 8, 7, 1, 2, 5, 3]
[1, 2, 3, 5, 7, 8, 9]
[1, 2, 3, 5, 7, 8, 9]
[9, 8, 7, 5, 3, 2, 1]