ruby 字符串处理函数总结列表 

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:

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"

 

4.字符串分隔,默认分隔符为空格

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", "l", "o"]

"hello".split(//, 3)

#=> ["h", "e", "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"]

"1,2,,3,4,,".split(',', 4)

#=> ["1", "2", "", "3,4,,"]

 

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>')

#=> "hll"   #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" Ruby

 

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  "

"hello".lstrip.rstrip

#=> "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\n\r还是普通字符

"hello".chomp

#=> "hello"

"hello\n".chomp

#=> "hello"

"hello\r\n".chomp

#=> "hello"

"hello\n\r".chomp

#=> "hello\n"

"hello\r".chomp

#=> "hello"

"hello".chomp("llo")

#=> "he"

"string\r\n".chop

 #=> "string"

"string\n\r".chop

#=> "string\n"

"string\n".chop

#=> "string"

"string".chop

#=> "strin"

 

ruby 取子串：

aa = "happy"

aa[0,1]    为'h' ，取子串。

详情请参考 http://www.runoob.com/ruby/ruby-string.html