Javascript - masking account number within a strin

问题:

I have a fun challenge I couldn't find an answer for here. I have a string of text, that could potentially contain an account number. Example:

"Hi, my account number is 1234 5678 9012 2345 and I'm great."

The account number can come in many flavours, as it's entered by the user:

Basic and potential possibilities below:

1234 1234 1234 1234
1234 1234 1234 1234 1
BE12 1234 1234 1234

1234-1234-1234-1234
1234.1234.1234.1234
1234123412341234
12341234 1234 1234

1234-1234-1234-1234-1
1234.1234.1234.1234.1
12341234123412341
12341 234 1234 12341

BE12-1234-1234-1234
be12-1234-1234 1234
Be12.1234.1234-1234
BE12123412341234

(basically integers with hyphen, space or a dot in the middle, with the exception of IBAN format, that has two characters at the beginning)

What I need as output is everything masked, except the last four digits.

"Hi, my account number is **** **** **** 2345 and I'm great."

How I think I should approach this problem:

• Analyze every string and try to find the above account no. patterns
• Create a magical regular expression that replaces the account no. they way I need
• If there's an account number, use this RegEx to do so.

What would be your approach?

Thanks!

回答1:

You could match all of the above with:

\b[\dX][-. \dX]+(\d{4})\b

... and replace it with * x strlen(match) - 4 + \1, see a demo on regex101.com.

---

In JavaScript:

var string = "Hi, my account number is 1234 5678 9012 2345 and I'm great.";
var new_string = string.replace(/\b[\dX][-. \dX]+(\d{4})\b/g, function(match, capture) {
    return Array(match.length-4).join("*") + capture;
});
print(new_string);

See a demo on ideone.com.

回答2:

Borrowing Jan's awesome regex pattern, it can be extended to capture the last digit too (see the example below)

Note: His method of using replace() is better, I recommend using it for clarity. This is only to offer an alternative approach using match()

//  Setup
let str = `1234 1234 1234 1234
1234-1234-1234-1234
12341234123412341234
1234 1234 1234 1234 1
12341234123412341
1234-1234-1234-1234-1
1234.1234.1234.1234.1
XX12 3456 1234 1234
XX123456123123
XX12-3456-1234-1234
XX12.3456.1234.1234
This is a sentence for visual proof 1234 5678 9012 3456
And some XX32 1111.2222-9999-2 more proof`,
  nums = str.split('\n');


var re = new RegExp(/(\b[\dX][-. \dX]+(\d{4}.?\d?)\b)/);

// Convert Nums
var converted = nums.map(num => {
  let match = num.match(re);

  if (match) {
    let orig = match[1],
      end    = match[2],
      hidden = orig.substr(0, orig.length - end.length);

    hidden = hidden.replace(/\S/g, "X") + end;
    num    = num.replace(orig, hidden);
  }

  return num;
});

// Visual Verification
console.log(converted);

回答3:

str.replace(/\b[\dX][-. \dX]+(\d{4})\b/g, '**** **** **** $1')

console.log("Hi, my account number is 1234-5678-9012-2345 and I'm great.".replace(/\b[\dX][-. \dX]+(\d{4})\b/g, '**** **** **** $1'));
console.log("Hi, my account number is 1234 5678 9012 2345 and I'm great.".replace(/\b[\dX][-. \dX]+(\d{4})\b/g, '**** **** **** $1'));
console.log("Hi, my account number is 1234.5678.9012.2345.1 and I'm great.".replace(/\b[\dX][-. \dX]+(\d{4})\b/g, '**** **** **** $1'));
console.log("Hi, my account number is XX123456123123 and I'm great.".replace(/\b[\dX][-. \dX]+(\d{4})\b/g, '**** **** **** $1'));

回答4:

Use a Regex with a look ahead trick, simply find

\d{4}([ -.])(?![A-Za-z])

and replace with

****\1