字符串分割成数组：
可以使用先scan再join的方法，当然其实有更好的 split方法，专门用来分割字符串
1 # 在Ruby中，如果不使用inspect，直接使用puts输出数组，那么每个元素会占用一行输出 2 irb(main):001:0> puts "Short sentence.Another.No more".split(/\./) 3 Short sentence 4 Another 5 No more 6 => nil 7 irb(main):002:0> puts "Short sentence.Another.No more".split(/\./).inspect 8 ["Short sentence", "Another", "No more"] 9 => nil
Split
数组迭代：
可以直接使用each方法来对每个元素进行遍历输出：
1 irb(main):005:0> a = [1, 2, 3, 4] 2 => [1, 2, 3, 4] 3 # collection对每一个元素进行迭代，返回的结果作为新的数组结果 4 irb(main):009:0> b = a.collect do |element| element*2 end 5 => [2, 4, 6, 8] 6 irb(main):010:0> b 7 => [2, 4, 6, 8] 8 # 如果不对元素进行任何操作，则返回的为同样个数每个元素为nil的数组 9 irb(main):011:0> b = a.collect do |element| puts element end 10 1 11 2 12 3 13 4 14 => [nil, nil, nil, nil] 15 irb(main):012:0> b 16 => [nil, nil, nil, nil] 17 # each永远返回原来的数组，没法改变原来的数组 18 irb(main):013:0> b = a.each do |element| end 19 => [1, 2, 3, 4] 20 irb(main):014:0> b 21 => [1, 2, 3, 4] 22 irb(main):015:0> b = a.each do |element| element*3 end 23 => [1, 2, 3, 4] 24 irb(main):016:0> b 25 => [1, 2, 3, 4] 26 # each一般用来进行相关操作 27 irb(main):018:0> a.each do |element| puts element end 28 1 29 2 30 3 31 4 32 => [1, 2, 3, 4]
ArrayIterator
ruby中的数组声明同java，最后一个,(逗号) 可要可不要
数组的其他操作：
1 irb(main):019:0> b = [2, 3, 4, 5] 2 => [2, 3, 4, 5] 3 # 数组支持 + -，相当于Redis中的UNION和DIFF。返回操作之后的数组，原数组不会变 4 irb(main):020:0> a - b 5 => [1] 6 # 判断是否为空 7 irb(main):021:0> puts "a is not empty" unless a.empty? 8 a is not empty 9 => nil 10 # 判断是否包含某元素 11 irb(main):022:0> a.include?(3) 12 => true 13 # 返回第一个元素 14 irb(main):023:0> a.first 15 => 1 16 # 返回最后一个元素 17 irb(main):024:0> a.last 18 => 4 19 # 返回开始的3个元素 20 irb(main):025:0> a.first(3) 21 => [1, 2, 3] 22 irb(main):026:0> a.last(3) 23 => [2, 3, 4] 24 # 逆序 25 irb(main):027:0> a.reverse 26 => [4, 3, 2, 1] 27 # 原数组不会变 28 irb(main):028:0> a 29 => [1, 2, 3, 4]
OtherOp
散列表：
1 # 基本形式
2 irb(main):029:0> dict = {‘cat‘=>‘cat1‘, ‘dog‘=>‘dog1‘}
3 => {"cat"=>"cat1", "dog"=>"dog1"}
4 # key必须为字符串或者标志
5 irb(main):030:0> dict2 = {cat=>cat1}
6 NameError: undefined local variable or method `cat‘ for main:Object
7 Did you mean? catch
8 from (irb):30
9 from /usr/bin/irb:11:in `<main>‘
10 irb(main):031:0> dict2 = {‘cat‘=>cat1}
11 NameError: undefined local variable or method `cat1‘ for main:Object
12 Did you mean? catch
13 from (irb):31
14 from /usr/bin/irb:11:in `<main>‘
15 irb(main):032:0> dict2 = {:cat=>‘cat1‘}
16 => {:cat=>"cat1"}
17 # length和size都可以得到长度
18 irb(main):033:0> dict.length
19 => 2
20 irb(main):034:0> dict.size
21 => 2
22 irb(main):035:0> dict[‘cat‘]
23 => "cat1"
24 # 不支持.访问
25 irb(main):036:0> dict.cat
26 NoMethodError: undefined method `cat‘ for {"cat"=>"cat1", "dog"=>"dog1"}:Hash
27 from (irb):36
28 from /usr/bin/irb:11:in `<main>‘
Hash
迭代散列表：
1 irb(main):037:0> dict.each do |key, value| puts "#{key} matches #{value}" end
2 cat matches cat1
3 dog matches dog1
4 => {"cat"=>"cat1", "dog"=>"dog1"}
Iterator
得到散列中的所有键和值:
1 irb(main):038:0> dict.keys.inspect 2 => "[\"cat\", \"dog\"]" 3 irb(main):039:0> dict.values.inspect 4 => "[\"cat1\", \"dog1\"]"
KeysValues
删除散列中的元素：
1 # 直接删除
2 => "[\"cat1\", \"dog1\"]"
3 irb(main):040:0> dict.delete(‘cat‘)
4 => "cat1"
5 irb(main):041:0> dict
6 => {"dog"=>"dog1"}
7 # 有条件的删除
8 irb(main):042:0> dict.delete_if do |key, value| value == ‘dog1‘ end
9 => {}
10 irb(main):043:0> dict
11 => {}
Delete
添加元素：
可以利用merge小技巧
1 irb(main):053:0> dict.merge({‘dog‘=>‘dog1‘})
2 => {"dog"=>"dog1"}
3 irb(main):054:0> dict.merge({‘cat‘=>‘cat1‘, ‘newDog‘=>‘dog2‘, ‘newCat‘=>‘cat2‘})
4 => {"cat"=>"cat1", "newDog"=>"dog2", "newCat"=>"cat2"}
5 # 发现merge只是返回一个新的hash，不能改变原来的hash
6 irb(main):055:0> dict
7 => {}
8 # 可以通过下面的方式巧妙的添加元素：
9 irb(main):057:0> dict = dict.merge({‘cat‘=>‘cat1‘, ‘newDog‘=>‘dog2‘, ‘newCat‘=>‘cat2‘})
10 => {"cat"=>"cat1", "newDog"=>"dog2", "newCat"=>"cat2"}
11 irb(main):058:0> dict
12 => {"cat"=>"cat1", "newDog"=>"dog2", "newCat"=>"cat2"}
Add
散列表中可以嵌套散列表，我们可以通过多重key值进行访问
1 # 散列中的元素也可以是散列值
2 irb(main):059:0> dict = dict.merge({‘animal‘=>{‘insideCat‘=>‘cat3‘}})
3 => {"cat"=>"cat1", "newDog"=>"dog2", "newCat"=>"cat2", "animal"=>{"insideCat"=>"cat3"}}
4 irb(main):060:0> dict[‘animal‘]
5 => {"insideCat"=>"cat3"}
6 # 可以嵌套获取值
7 irb(main):061:0> dict[‘animal‘][‘insideCat‘]
8 => "cat3"
InsideHash
流程控制：
if 、unless
if elsif
case:
1 fruit = ‘orange‘ 2 irb(main):084:0> case fruit 3 irb(main):085:1> when ‘orange‘ 4 irb(main):086:1> color = ‘orange‘ 5 irb(main):087:1> when ‘apple‘ 6 irb(main):088:1> color = ‘green‘ 7 irb(main):089:1> else 8 irb(main):090:1* color = ‘unknown‘ 9 irb(main):091:1> end 10 => "orange" 11 12 # 上例可以简化为 13 irb(main):092:0> color = case fruit 14 irb(main):093:1> when ‘orange‘ 15 irb(main):094:1> ‘orange‘ 16 irb(main):095:1> else ‘unknown‘ end 17 => "orange" 18 irb(main):096:0> color 19 => "orange"
Case
while
until:与while相反，直到条件满足才跳出循环
1 irb(main):097:0> x = 1 2 => 1 3 irb(main):098:0> until x > 99 4 irb(main):099:1> puts x 5 irb(main):100:1> x = x * 20 6 irb(main):101:1> end 7 1 8 20 9 => nil
Until
时间： 2024-08-12 19:17:44