我有一个包含内容的字符串变量：
varMessage =
"hi/thsid/sdfhsjdf/dfjsd/sdjfsdn\n"
"/my/name/is/balaji.so\n"
"call::myFunction(int const&)\n"
"void::secondFunction(char const&)\n"
.
.
.
"this/is/last/line/liobrary.so"
在字符串中，我必须找到一个子字符串：
"hi/thsid/sdfhsjdf/dfjsd/sdjfsdn\n"
"/my/name/is/balaji.so\n"
"call::myFunction(int const&)\n"
我怎样才能找到它？我需要确定子字符串是否存在。
当前回答
可以使用字符串元素引用方法，该方法为[]
[]内可以是文本子字符串、索引或正则表达式：
> s='abcdefg'
=> "abcdefg"
> s['a']
=> "a"
> s['z']
=> nil
由于nil在功能上与false相同，并且从[]返回的任何子字符串都是true，因此您可以像使用方法一样使用逻辑。include？：
0> if s[sub_s]
1> puts "\"#{s}\" has \"#{sub_s}\""
1> else
1* puts "\"#{s}\" does not have \"#{sub_s}\""
1> end
"abcdefg" has "abc"
0> if s[sub_s]
1> puts "\"#{s}\" has \"#{sub_s}\""
1> else
1* puts "\"#{s}\" does not have \"#{sub_s}\""
1> end
"abcdefg" does not have "xyz"
请确保不要将索引与子字符串混淆：
> '123456790'[8] # integer is eighth element, or '0'
=> "0" # would test as 'true' in Ruby
> '123456790'['8']
=> nil # correct
也可以使用正则表达式：
> s[/A/i]
=> "a"
> s[/A/]
=> nil
其他回答
user_input = gets.chomp
user_input.downcase!
if user_input.include?('substring')
# Do something
end
这将帮助您检查字符串是否包含子字符串
puts "Enter a string"
user_input = gets.chomp # Ex: Tommy
user_input.downcase! # tommy
if user_input.include?('s')
puts "Found"
else
puts "Not found"
end
你可以使用include？方法：
my_string = "abcdefg"
if my_string.include? "cde"
puts "String includes 'cde'"
end
可以使用字符串元素引用方法，该方法为[]
[]内可以是文本子字符串、索引或正则表达式：
> s='abcdefg'
=> "abcdefg"
> s['a']
=> "a"
> s['z']
=> nil
由于nil在功能上与false相同，并且从[]返回的任何子字符串都是true，因此您可以像使用方法一样使用逻辑。include？：
0> if s[sub_s]
1> puts "\"#{s}\" has \"#{sub_s}\""
1> else
1* puts "\"#{s}\" does not have \"#{sub_s}\""
1> end
"abcdefg" has "abc"
0> if s[sub_s]
1> puts "\"#{s}\" has \"#{sub_s}\""
1> else
1* puts "\"#{s}\" does not have \"#{sub_s}\""
1> end
"abcdefg" does not have "xyz"
请确保不要将索引与子字符串混淆：
> '123456790'[8] # integer is eighth element, or '0'
=> "0" # would test as 'true' in Ruby
> '123456790'['8']
=> nil # correct
也可以使用正则表达式：
> s[/A/i]
=> "a"
> s[/A/]
=> nil
三元法
my_string.include?('ahr') ? (puts 'String includes ahr') : (puts 'String does not include ahr')
OR
puts (my_string.include?('ahr') ? 'String includes ahr' : 'String not includes ahr')
如果你不能使用上面提到的任何一个库，你可以通过简单的文本搜索来实现同样的效果（这是因为降格而忽略大小写）：
ADD_BUTTON_TEXTS = ["add to cart", "add to basket"].freeze
target_text = "AdD tO cArT"
ADD_BUTTON_TEXTS.each do |text|
puts "Text was found" if target_text.downcase.include?(text)
end
