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Ruby:字符串处理函数

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简介:字符串处理函数 1.返回字符串的长度 str.length=>integer   2.判断字符串中是否包含另一个串

字符串处理函数


1.返回字符串的长度

str.length => integer

 

2.判断字符串中是否包含另一个串

str.include? other_str => true or false

"hello".include? "lo" #=> true

"hello".include? "ol" #=> false

"hello".include? ?h #=> true

 

3.字符串插入:

Ruby:字符串处理函数

str.insert(index,other_str) => str

"abcd".insert(0,'X') #=> "Xabcd"

"abcd".insert(3,'X') #=> "abcXd"

"abcd".insert(4,'X') #=> "abcdX"

"abcd".insert(-3,'X')

-3,'X') #=> "abXcd"

"abcd".insert(-1,'X') #=> "abcdX"

Ruby:字符串处理函数

 

4.字符串分隔,默认分隔符为空格

Ruby:字符串处理函数

str.split(pattern=$;,[limit]) => anArray

" now's the time".split #=> ["now's","the","time"]

"1,2.34,56,7".split(%r{,s*}) #=> ["1","2.34","56","7"]

"hello".split(//) #=> ["h","e","l","o"]

"hello".split(//,3) #=> ["h","llo"]

"hi mom".split(%r{s*}) #=> ["h","i","m","o","m"]

"mellow yellow".split("ello") #=> ["m","w y","w"]

"1,2,3,4,".split(',') #=> ["1","2","","3","4"]

"1,',4) #=> ["1","3,"]

Ruby:字符串处理函数

 

5.字符串替换

str.gsub(pattern,replacement) => new_str

str.gsub(pattern) {|match| block } => new_str

"hello".gsub(/[aeiou]/,'*') #=> "h*ll*" #将元音替换成*号

"hello".gsub(/([aeiou])/,'<1>') #=> "h<e>ll<o>" #将元音加上尖括号,1表示保留原有字符???

"hello".gsub(/./) {|s| s[0].to_s + ' '} #=> "104 101 108 108 111 "

字符串替换二:

str.replace(other_str) => str

s = "hello" #=> "hello"

s.replace "world" #=> "world"

 

6.字符串删除:

str.delete([other_str]+) => new_str

"hello".delete "l","lo" #=> "heo"

"hello".delete "lo" #=> "he"

"hello".delete "aeiou","^e" #=> "hell"

"hello".delete "ej-m" #=> "ho"

 

7.去掉前和后的空格

str.lstrip => new_str

" hello ".lstrip #=> "hello "

"hello".lstrip #=> "hello"

 

8.字符串匹配

str.match(pattern) => matchdata or nil

 

9.字符串反转

str.reverse => new_str

"stressed".reverse #=> "desserts"

 

10.去掉重复的字符

str.squeeze([other_str]*) => new_str

"yellow moon".squeeze #=> "yelow mon" #默认去掉串中所有重复的字符

" now is the".squeeze(" ") #=> " now is the" #去掉串中重复的空格

"putters shoot balls".squeeze("m-z") #=> "puters shot balls" #去掉指定范围内的重复字符

 

11.转化成数字

str.to_i=> str

"12345".to_i #=> 12345

 

chomp和chop的区别:


chomp:去掉字符串末尾的n或r


chop:去掉字符串末尾的最后一个字符,不管是nr还是普通字符

Ruby:字符串处理函数

"hello".chomp #=> "hello"

"hellon".chomp #=> "hello"

"hellorn".chomp #=> "hello"

"hellonr".chomp #=> "hellon"

"hellor".chomp #=> "hello"

"hello".chomp("llo") #=> "he"

"stringrn".chop #=> "string"

"stringnr".chop #=> "stringn"

"stringn".chop #=> "string"

"string".chop #=> "strin"

Ruby:字符串处理函数

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