JS is intercepting a string between two strings

Match method

var str = "IID0000FFR"; var substr = Str.match (/id (\s*) ff/); Console.log (SUBSTR)

The returned result is: ["id0000ff", "0000"]

The \s* expression in () matches all strings

In high-level languages, we use a concept called quantitative words:

(? =ff) This represents the preceding string with the FF ending, but does not include the FF

var str = "IID0000FFR"; var substr = Str.match (/(\s*) (? =ff)/); Console.log (SUBSTR)

return array: ["iid0000", "iid0000"]

　　

(iid=?) This represents a string that begins with the IID, but does not include the IID

var str = "IID0000FFR"; var substr = Str.match (/(iid=?) (\s*)/); Console.log (SUBSTR);

return array: ["IID0000FFR", "IID", "0000FFR"]

Get back and forth the middle string as the first example

var str = "IID0000FFR"; var substr = Str.match (/(iid=?) (\s*) (? =FFR)/); Console.log (SUBSTR);

return array: ["iid0000", "iid", "0000"]

JS is intercepting a string between two strings