lanourlee的专栏

1. Install Xcode and the Command Line Tools If you don't have it installed I suggest you install Xcode from the Mac App Store and install the command line tools in Xcode Preferences -> Downloads.

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