沒有什么特別的原因開學(xué)學(xué)習(xí)Ruby,，只是從興趣出發(fā)

轉(zhuǎn)化為數(shù)組
很簡(jiǎn)單，to_a方法搞定：
r = 3..12
arr = r.to_a     # [3,4,5,6,7,8,9,10,11,12]
digits = 0..9
digits.include?(5) -> true
digits.min -> 0
digits.max -> 9
digits.reject {|i| i < 5 } -> [5, 6, 7, 8, 9]
digits.each {|digit| dial(digit) } -> 0..9
('a'..'z').to_a.each{|i| puts i}   #顯示a到z的字符串
r1 = 3..6
r2 = 3...6     #....不包含上線6
r1a, r1b = r1.first, r1.last    # 3, 6
r1c, r1d = r1.begin, r1.end     # 3, 6
r2a, r2b = r2.begin, r2.end     # 3, 6 (注意：不是3和5)
r1 = "7".."9"
r2 = "7".."10"
r1.each {|x| puts x }   # 打印出7,8,9
r2.each {|x| puts x }   # 未打印任何東西
##為什么會(huì)出現(xiàn)這樣的情況,？這是因?yàn)檫@里都是字符串,，由于r1中,，"7"比"9"小
所以,，它是個(gè)合理的Range,；而表達(dá)式r2中，"7"比"10"大,，下限大于了上限,，就不合理了。
r1 = 23456..34567
x = 14142
y = 31416
r1.include?(x)      # false
r1.include?(y)      # true

3.times { print "X " }
1.upto(5) {|i| print i, " " }
99.downto(95) {|i| print i, " " }
50.step(80, 5) {|i| print i, " " }   #50至80之間步長(zhǎng)5

a -> 97 #ASCII值

f=File.open("testfile")
f.each{|line| puts line}
f.close

line=gets   #從鍵盤輸入負(fù)值給line
print line  #打印line

histogram = Hash.new() #新建一個(gè)Hash表
histogram['key1'] -> 0
histogram['key1'] = histogram['key1'] + 1
histogram['key1'] -> 1
histogram.default = "hello"  #沒有定義的key會(huì)返回hello

shift

char=[a,b,b,c].shift   #刪除數(shù)組中的第一個(gè)字符
puts char  # a

[1,3,5,7,9].find{|v| v*v < 30 }   #返回滿足條件的第一個(gè)值
["H", "A", "L"].collect {|x| x.succ }  #輸下當(dāng)前字符的下一字符
[1,3,5,7,9].each{|i| puts i }   #遍歷數(shù)組
[1,3,5,7].inject {|sum, element| sum+element}                    #數(shù)組求和
[1,3,5,7].inject {|product, element| product*element}        #數(shù)組求積
a=Array.new  #新建一個(gè)數(shù)組
a = [ 'ant', 'bee', 'cat', 'dog', 'elk' ]
a[0] -> "ant"
a[3] -> "dog"
# this is the same:
a = %w{ ant bee cat dog elk }
a[0] -> "ant"
a[3] -> "dog"
a.length -> 5  #數(shù)組長(zhǎng)度,，變量為字符串長(zhǎng)度

全局變量 用$開頭
實(shí)例變量 用@開頭
類變量 用@@ 開頭

person = "Tim"
person.id -> 936870
person.class -> String
person -> "Tim"

#{..} → 可以在引號(hào)中引用變量值或

def say_goodnight(name)
result = "Good night, #{name.capitalize}" #.capitalize輸出字符串首字母大寫
return result
end
puts say_goodnight('uncle')
輸出結(jié)果:
Good night, Uncle

squeeze

我們可以使用squeeze 方法來一處重復(fù)的字符
s1 = "bookkeeper"
puts s2 = s1.squeeze         # "bokeper"
s3 = "Hello..."
puts s4 = s3.squeeze         # "Helo."
#If a parameter is specified, only those characters will be squeezed.
puts s5 = s3.squeeze(".")    # "Hello."

將一個(gè)字符串按照單詞進(jìn)行反轉(zhuǎn),，那么你就會(huì)用到split方法和，數(shù)組的reverse方法

phrase = "Now here's a sentence"
puts phrase.split(" ").reverse.join(" ")
# "sentence a here's Now"

strip

strip將會(huì)刪除掉字符串的開頭和結(jié)尾的空格
sss="a d c "
puts sss.strip  => abc
如果你只想從字符串的開頭或者結(jié)尾的空格,，那么可以使用lstrip或者rstrip
str = "  abc  "
s2 = str.lstrip       # "abc  "
s3 = str.rstrip       # "  abc"

chop

chop方法將會(huì)刪除最后一個(gè)字符,，返回新的string。如果字符是以\r\n結(jié)束,，則兩個(gè)字符都會(huì)被刪除
str = "abcxyz"
s1 = str.chop           # "abcxy"
str2="abc\r\n"
s2=str2.chop  #abc

chomp

str = "abcxyz"
puts s1 = str.chomp #abcxyz
str2 = "123\n"
puts s2=str2.chomp   #123
str1 = "abcxyz"
str2 = "abcxyz"
puts s1 = str1.chomp("yz")   # "abcx"
puts s2 = str2.chomp("x")    # "abcxyz"   #只匹配結(jié)尾的詞

unpack

puts  "E".unpack("c")    #69   輸出一個(gè)字符串的asc碼值

?

puts  "a"<<111    <<符號(hào)或者chr來把一個(gè)asc轉(zhuǎn)換為字符串:
puts  111.chr

scan

"hello world".scan(/./){|s| print s}  #掃描匹配的字符串并打印

casecmp

n4 = "ABC".casecmp("abc")   # 0 功能同<=>忽略大小寫

puts

str="bobo"
puts str.ljust(8,"++")    #左對(duì)齊其余用++補(bǔ)齊
puts str.rjust(8,"++")    #右對(duì)齊其余用++補(bǔ)齊

"Seconds/day: #{24*60*60}" -> Seconds/day: 86400
"#{'Ho! '*3}Merry Christmas!" -> Ho! Ho! Ho! Merry Christmas!
"This is line #$." -> This is line 3         # #?顯示程序塊中語(yǔ)句所在的行號(hào)

each_byte

str="bobo"
str.each_byte{|byte| puts byte.chr}
結(jié)果：
b
o
b
o

dup

person1 = "Tim"
person2 = person1.dup   #同.new功能相同也可以用person2=person1
person1[0] = "J"
person1 -> "Jim"
person2 -> "Tim"

freeze

person1 = "Tim"
person2 = person1
person1.freeze   # 字符串不可變
person2[0] = "J"
結(jié)果：
prog.rb:4:in `[]=': can't modify frozen string (TypeError)
from prog.rb:4

index & rindex

index方法返回指定的子字符串,，正則表達(dá)式或者字符的起始位置(如果有多個(gè)匹配的只返回第一個(gè)匹配的起始位置)
沒有發(fā)現(xiàn)的話返回nil,而rindex則是從string的右邊(也就是結(jié)束處)開始查找，不過返回的值卻是從左邊數(shù)起的：
str = "Albert Einstein"
puts pos1 = str.index(?E)        # 7
puts pos1 = str.index(69)        # 7
puts pos2 = str.index("bert")    # 2
puts pos3 = str.index(/in/)      # 8
puts pos4 = str.index(?e)        # nil
puts pos5 = str.index("bart")    # nil
puts pos6 = str.index(/wein/)    # nil

正側(cè)表達(dá)式

sub或者gsub方法來進(jìn)行替換,，他們兩個(gè)方法第一個(gè)參數(shù)都是接受正則表達(dá)式,。
其中，sub方法替換掉第一個(gè)匹配的地方,，而gsub方法替換掉全部匹配的地方：
s1 = "spam, spam, and eggs"
s2 = s1.sub(/spam/,"bacon")               # "bacon, spam, and eggs"
s3 = s2.sub(/(\w+), (\w+),/,'\2, \1,')    # "spam, bacon, and eggs"
s4 = "Don't forget the spam."
s5 = s4.sub(/spam/) { |m| m.reverse }     # "Don't forget the maps."  把匹配部分的單詞反轉(zhuǎn)
s5 = "alfalfa abracadabra"
s6 = s5.gsub(/a[bl]/,"xx")     # "xxfxxfa xxracadxxra"
s5.gsub(/[lfdbr]/) { |m| m.upcase + "-" }
# s5 is now "aL-F-aL-F-a aB-R-acaD-aB-R-a"

ruby打印輸出命令
puts 帶換行符輸出
priint 不帶換行符輸出
ruby中區(qū)間表示
1..5表示1，2,，3,，4，5
1...5表示1,，2,，3，4