正则表达式，用于捕获ID中的4个连续数字

Question

I need a formula to start at aa certain index and then get the next 4 consecutive numbers. Using REGEX. And testing whether they are in the range of 0000-4999.

^.{6}\d{4}$[0000-4999]

This is some code I have tried. Although I'm still new and don't understand regex.

The outcome needs to be as follows:

ID Number:

9202204720082

Get the following 4 numbers: 4720

Starting at index 7 (presuming indexes starts at 1)

So want to get numbers if indexes 7,8,9, and 10. This is done to determine the gender in an ID.

Answer 1

May be this can help :

(?<=\d{6})\d{4}(?<=\d{3})

you can check it out in the regex101 link : Link to Regex

Answer 2

Your original expression is just fine, here we can slightly modify it to:

^.{6}(\d{4}).+$

which we are capturing our desired digits in this group (\\d{4}) .

DEMO

 const regex = /^.{6}(\\d{4}).+$/gm; const str = `9202204720082`; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); } 

RegEx Circuit

jex.im visualizes regular expressions:

Answer 3

You don't need to use a regex for this. You could achieve the same result by simply getting a substring. Depending on your programming language you might do something like this:

JavaScript

 var string = "9202204720082"; var index = 6; console.log(string.substring(index, index + 4)); 

Ruby

string = '9202204720082'
index = 6

string[index, 4]
#=> "4720"

Perl

my $string = '9202204720082';
my $index = 6;

substr($string, $index, 4);
#=> "4720"