Ruby Array

创建数组

irb(main):001:0> a&＃61;[1,2,3]
&＃61;> [1, 2, 3]
irb(main):002:0> b&＃61;["1",2,3.14]
&＃61;> ["1", 2, 3.14]
irb(main):003:0> c&＃61;Array.new
&＃61;> []
irb(main):004:0> d&＃61;Array.new(5)
&＃61;> [nil, nil, nil, nil, nil]
irb(main):005:0> e&＃61;Array.new(5,0)
&＃61;> [0, 0, 0, 0, 0]
irb(main):006:0> la&＃61;%w(Ruby Perl Python Scheme Pike REBOL)
&＃61;> ["Ruby", "Perl", "Python", "Scheme", "Pike", "REBOL"]
irb(main):007:0> li&＃61;%i(Ruby Perl Python Scheme Pike REBOL)
&＃61;> [:Ruby, :Perl, :Python, :Scheme, :Pike, :REBOL]
irb(main):008:0> color_table&＃61;{black:"#000000",white:"#FFFFF"}
&＃61;> {:black&＃61;>"#000000", :white&＃61;>"#FFFFF"}
irb(main):009:0> color_table.to_a
&＃61;> [[:black, "#000000"], [:white, "#FFFFF"]]
irb(main):010:0> column&＃61;"1 2 3 4 5 8 0".split
&＃61;> ["1", "2", "3", "4", "5", "8", "0"]

索引的使用

li[0]
&＃61;> :Ruby
irb(main):012:0> li[4]
&＃61;> :Pike
irb(main):013:0> a[1..2]
&＃61;> [2, 3]
irb(main):014:0> a[0...3]
&＃61;> [1, 2, 3]
irb(main):015:0> a[0..3]
&＃61;> [1, 2, 3]
irb(main):016:0> a[0..2]
&＃61;> [1, 2, 3]
irb(main):017:0> a[0,2]
&＃61;> [1, 2]
irb(main):018:0> a[0,3]
&＃61;> [1, 2, 3]
irb(main):019:0> a[-1]
&＃61;> 3
irb(main):020:0> a[-1,2]
&＃61;> [3]
irb(main):021:0> a[-2]
&＃61;> 2
irb(main):022:0> a[-3]
&＃61;> 1
irb(main):023:0> a[-4]
&＃61;> nil
irb(main):024:0> li
&＃61;> [:Ruby, :Perl, :Python, :Scheme, :Pike, :REBOL]
irb(main):025:0> li[0]&＃61;:china
&＃61;> :china
irb(main):026:0> li
&＃61;> [:china, :Perl, :Python, :Scheme, :Pike, :REBOL]
irb(main):027:0> li[2,0]&＃61;[:X,:Y]
&＃61;> [:X, :Y]
irb(main):028:0> li
&＃61;> [:china, :Perl, :X, :Y, :Python, :Scheme, :Pike, :REBOL]

将数组用作集合

&: 集合的交&＃xff0c;&＃xff5c;&＃xff1a;集合的并&＃xff0c;-:集合的差&＃xff0c;&＃xff0b;:集合的连接

irb(main):029:0> ary1&＃61;"a b c".split
&＃61;> ["a", "b", "c"]
irb(main):030:0> ary2&＃61;"b c d".split
&＃61;> ["b", "c", "d"]
irb(main):031:0> ary1 & ary2
&＃61;> ["b", "c"]
irb(main):032:0> ary1 | ary2
&＃61;> ["a", "b", "c", "d"]
irb(main):033:0> ary1 - ary2
&＃61;> ["a"]
irb(main):034:0> ary2- ary1
&＃61;> ["d"]
irb(main):035:0> ary1 &＃43; ary2
&＃61;> ["a", "b", "c", "b", "c", "d"]

数组用作栈、队列

栈

a&＃61;[1,3,2,4]
a.push 99 #a&＃61;[1,2,3,4,99]
a.pop #99 a&＃61;[1,2,3,4]

队列

a&＃61;[1,2,3,4]
a.push 99 #a&＃61;[1,2,3,4,99]
a.shift #1 a&＃61;[2,3,4,99]

数组的主要方法

irb(main):042:0> a
&＃61;> [2, 46, 7, 8]
irb(main):043:0> a.unshift 10
&＃61;> [10, 2, 46, 7, 8]
irb(main):044:0> a<<1000
&＃61;> [10, 2, 46, 7, 8, 1000]
irb(main):045:0> a.push 1001
&＃61;> [10, 2, 46, 7, 8, 1000, 1001]
irb(main):046:0> a.concat "16 15 11".split
&＃61;> [10, 2, 46, 7, 8, 1000, 1001, "16", "15", "11"]
irb(main):047:0> a&＃43; [111,112,113]
&＃61;> [10, 2, 46, 7, 8, 1000, 1001, "16", "15", "11", 111, 112, 113]
irb(main):048:0> ary&＃61;[13,nil,666,nil,777,nil,999,nil]
&＃61;> [13, nil, 666, nil, 777, nil, 999, nil]
irb(main):049:0> ary.compact
&＃61;> [13, 666, 777, 999]
irb(main):050:0> a.delete 111
&＃61;> nil
irb(main):051:0> a
&＃61;> [10, 2, 46, 7, 8, 1000, 1001, "16", "15", "11"]
irb(main):052:0> a.delete_at 2
&＃61;> 46
irb(main):053:0> a
&＃61;> [10, 2, 7, 8, 1000, 1001, "16", "15", "11"]
irb(main):054:0> a.delete_if{|item| item.class&＃61;&＃61;String}
&＃61;> [10, 2, 7, 8, 1000, 1001]
irb(main):055:0> a.reject {|item| item>&＃61;1000}
&＃61;> [10, 2, 7, 8]
irb(main):056:0> a.slice 1,2
&＃61;> [2, 7]
irb(main):057:0> d&＃61;[1,1,1,3,4,6,6,8,9]
&＃61;> [1, 1, 1, 3, 4, 6, 6, 8, 9]
#获取只出现一次的元素
irb(main):059:0> d.uniq
&＃61;> [1, 3, 4, 6, 8, 9]
irb(main):060:0> d.shift
&＃61;> 1
irb(main):061:0> d
&＃61;> [1, 1, 3, 4, 6, 6, 8, 9]
irb(main):062:0> a.pop
&＃61;> 1001
irb(main):063:0> a
&＃61;> [10, 2, 7, 8, 1000]

collect,map,fill

irb(main):064:0> arr&＃61;[6,4,3,6,9,8]
&＃61;> [6, 4, 3, 6, 9, 8]
irb(main):065:0> arr.collect{|item| item**2}
&＃61;> [36, 16, 9, 36, 81, 64]
irb(main):066:0> a.map{|item| item*2}
&＃61;> [20, 4, 14, 16, 2000]
irb(main):067:0> arr.map{|item| item*2}
&＃61;> [12, 8, 6, 12, 18, 16]
irb(main):068:0> x&＃61;Array.new
&＃61;> []
irb(main):071:0> x<<1
&＃61;> [1]
irb(main):072:0> x<<111
&＃61;> [1, 111]
irb(main):073:0> x<<222
&＃61;> [1, 111, 222]
irb(main):074:0> x.fill(0) #将所有值替换为0
&＃61;> [0, 0, 0]
irb(main):075:0> y&＃61;[1,111,222]#
&＃61;> [1, 111, 222]
irb(main):076:0> y.fill(-1,1) #将索引为1处的值替换为-1
&＃61;> [1, -1, -1]
irb(main):077:0> y.fill 1000,1,1 #fill(value,begin,len)
&＃61;> [1, 1000, -1]

flatten,sort,sort_by

irb(main):078:0> e&＃61;[]
&＃61;> []
irb(main):079:0> e<<[1,3]
&＃61;> [[1, 3]]
irb(main):080:0> e<<[2,4]
&＃61;> [[1, 3], [2, 4]]
irb(main):081:0> e<<[9,0]
&＃61;> [[1, 3], [2, 4], [9, 0]]
irb(main):082:0> e.flatten
&＃61;> [1, 3, 2, 4, 9, 0]
irb(main):083:0> e.reverse
&＃61;> [[9, 0], [2, 4], [1, 3]]
irb(main):084:0> f&＃61;e.flatten
&＃61;> [1, 3, 2, 4, 9, 0]
irb(main):085:0> f.sort{|i,j| i<&＃61;>j}
&＃61;> [0, 1, 2, 3, 4, 9]
irb(main):086:0> f.sort_by{|item| -item}
&＃61;> [9, 4, 3, 2, 1, 0]

获取数组的各元素值

list&＃61;[1,3,5,7,9]
&＃61;> [1, 3, 5, 7, 9]
irb(main):094:0> sum&＃61;0
&＃61;> 0
irb(main):095:0> list.each do |item|
irb(main):096:1* sum&＃43;&＃61;item
irb(main):097:1> end
&＃61;> [1, 3, 5, 7, 9]
irb(main):098:0> sum
&＃61;> 25
irb(main):099:0> list.each_with_index do |item,index|
irb(main):100:1* p item,index end
1
0
3
1
5
2
7
3
9
4

访问多个数组

irb(main):101:0> ary1&＃61;[1,2,3]
&＃61;> [1, 2, 3]
irb(main):102:0> ary2&＃61;[100,200,300]
&＃61;> [100, 200, 300]
irb(main):103:0> ary3&＃61;[5,4,3]
&＃61;> [5, 4, 3]
irb(main):104:0> ary1.zip ary2,ary3 do |a,b,c|
irb(main):105:1* p a.to_s&＃43;" "&＃43;b.to_s&＃43;" "&＃43;c.to_s end
"1 100 5"
"2 200 4"
"3 300 3"
&＃61;> nil