Ruby / Regex解析字符串

Question

I'd like to take a string and split it into an array only if its format is valid

Valid formats for the string include:

• key: Bob value: 5000
• key: Jane value: 6000,700,100

An invalid format, besides key: or value: being spelled wrong:

• key: Bob value: 6000,,,,100

I've been using gets to get a line and trying to use this code:

if line =~ /key:\s\d+\svalue:\s([\d+]+,?)*/
 # do stuff
end  

I also tried using === but both just return true / not nil for both valid and invalid strings. How can I ensure that multiple consecutive commas is considered invalid?

Answer 1

I tend to use split in situations like this:

str = "key: Bob value: 5000,330,200"
 => "key: Bob value: 5000,330,200" 

arr = str.split
 => ["key:", "Bob", "value:", "5000,330,200"] 

if arr[0] == "key:" && arr[2] == "value:" && arr[3].split(",").none?(&:empty?)
  # do stuff
end

Easier for me to suss out.

Answer 2

"affirmative" match :

^key:\\s\\w+\\svalue:\\s(\\d+,?)+$ //better validation

"negative" match :

^(?!.*,,).*$ //simple negative lookahead