ruby学习-字符串
字符串
1.创建字符1:new用来创建新字符,empty?检验字符是否为空
title = String.new #=> ""
title.empty? #=>true
创建字符2:用"="
str = "hello"或者str='hello'(ps:单/双 引号区别," "会转义,' '原样输出,"\n"是换行效果)
2.通用分隔符 %+例如!!,{},[]
str = %! hehe !
3.嵌入文档
sonnet =<<30
this is a language i think good
do u know
30
puts sonnet
4.字符连接
+,<<,.contact方法(此只连一个字符串)
Object.freeze冻结字符串,禁止改变
5.字符串访问
e.g. str="a horse!"
str['hor']#若存在'hor则返回‘hor',否则返回nil表示搜索字符串不存在。
str[7]#=>33,因为是个"!",其字符编码是33,
所以str[7].chr #=>"!"
str[2,2]#=>"ho", str[2,2].capitalize#=>"Ho"
str[0..3]#=>a ho而 str[0...3]#=>a h 三个点表示不包括最后一个字符
6.字符串比较:
<=>比较的是字符编码,-1,0,1代表小于,等于,大于"a" <=>"a" #=>0
而casecmp则会忽略大小写"a"<=>"A" #=>1,"a".casecmp "A" #=>0
6.字符操作:
6.1字符插入:insert方法
"Be careful".insert 3,"very " #=>Be very careful
6.2字符替换
str="sun of bitch"
(1) str["bitch"]="brother" #=>sun of brother
(2) str[7]="a " #=>sun of a bitch
(3) str[3,11]="shine" #=>sunshine
(4)str[/bitch$/]="brother" #正则表达式