is this code is write for validation of adhaar number

[suyash012]

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var d = [
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
[1, 2, 3, 4, 0, 6, 7, 8, 9, 5],
[2, 3, 4, 0, 1, 7, 8, 9, 5, 6],
[3, 4, 0, 1, 2, 8, 9, 5, 6, 7],
[4, 0, 1, 2, 3, 9, 5, 6, 7, 8],
[5, 9, 8, 7, 6, 0, 4, 3, 2, 1],
[6, 5, 9, 8, 7, 1, 0, 4, 3, 2],
[7, 6, 5, 9, 8, 2, 1, 0, 4, 3],
[8, 7, 6, 5, 9, 3, 2, 1, 0, 4],
[9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
];

// permutation table p
var p = [
    [0, 1, 2, 3, 4, 5, 6, 7, 8, 9], 
    [1, 5, 7, 6, 2, 8, 3, 0, 9, 4], 
    [5, 8, 0, 3, 7, 9, 6, 1, 4, 2], 
    [8, 9, 1, 6, 0, 4, 3, 5, 2, 7], 
    [9, 4, 5, 3, 1, 2, 6, 8, 7, 0], 
    [4, 2, 8, 6, 5, 7, 3, 9, 0, 1], 
    [2, 7, 9, 3, 8, 0, 6, 4, 1, 5], 
    [7, 0, 4, 6, 9, 1, 3, 2, 5, 8]
];

// inverse table inv
var inv = [0, 4, 3, 2, 1, 5, 6, 7, 8, 9];

// converts string or number to an array and inverts it
function invArray(array){
    if (Object.prototype.toString.call(array) == "[object Number]"){
        array = String(array);
    }
    
    if (Object.prototype.toString.call(array) == "[object String]"){
        array = array.split("").map(Number);
    }
    
    return array.reverse();
}

// generates checksum
function generate(array){
    var c = 0;
    var invertedArray = invArray(array);
    
    for (var i = 0; i < invertedArray.length; i++){
        c = d[c][p[((i + 1) % 8)][invertedArray[i]]];
    }
    
    return inv[c];
}

// validates checksum
function validate(array) {
    var c = 0;
    var invertedArray = invArray(array);
    
    for (var i = 0; i < invertedArray.length; i++){
        c = d[c][p[(i % 8)][invertedArray[i]]];
    }

    return (c === 0);
}

// Aadhaar error detection using proper Verhoeff algorithm
function checkAadhaarErrors(aadhaarNumber) {
    // Input validation
    if (!aadhaarNumber || typeof aadhaarNumber !== 'string') {
        return { hasError: true, message: "Please provide a valid Aadhaar number" };
    }
    
    const cleanNumber = aadhaarNumber.replace(/\D/g, '');
    
    // Basic format checks
    if (cleanNumber.length !== 12) {
        return { hasError: true, message: "Aadhaar must be 12 digits" };
    }

    // Check for obvious input errors
    if (new Set(cleanNumber).size === 1) {
        return { hasError: true, message: "All digits cannot be the same" };
    }

    // Enhanced pattern checks for common invalid sequences
    const invalidPatterns = [
        '123456789012', 
        '000000000000', 
        '123456789123',
        '987654321098',
        '111111111111',
        '222222222222',
        '333333333333',
        '444444444444',
        '555555555555',
        '666666666666',
        '777777777777',
        '888888888888',
        '999999999999'
    ];
    
    if (invalidPatterns.includes(cleanNumber)) {
        return { hasError: true, message: "Please enter your actual Aadhaar number" };
    }

    // Use proper Verhoeff validation
    const isValid = validate(cleanNumber);

    // If Verhoeff validation fails, there might be a typing error
    if (!isValid) {
        return { 
            hasError: true, 
            message: "Possible typing error detected. Please check your Aadhaar number",
            isTypingError: true 
        };
    }

    // No errors detected
    return { hasError: false, message: "Format looks correct" };
}

[JonathanZawadke]

Yes, the provided code correctly implements the Verhoeff algorithm, which is officially used for validating Aadhaar numbers in India.

Here’s what the code does well:

✅ It uses the correct multiplication table (d), permutation table (p), and inverse table (inv) as per the Verhoeff algorithm.
✅ The validate() function correctly computes the checksum and validates it.
✅ The checkAadhaarErrors() function adds important pre-checks, such as:

• Ensuring the input is 12 digits
• Rejecting known fake patterns (like all digits being the same or increasing sequences)
• Returning user-friendly error messages

Summary:
✔️ Yes, this code is well-written and suitable for Aadhaar number validation.
✔️ It’s a good example of combining algorithmic validation with user input checks to reduce false positives and catch common mistakes.

If you're planning to use this in production, ensure that:

• You handle input securely (e.g., prevent logging Aadhaar numbers)
• You do not use Aadhaar numbers for authentication or storage without complying with local privacy laws (e.g., UIDAI guidelines)

[naurjhanvi]

yes its correct

[github-actions[bot]]

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[FrandyAquino]

This implementation is a ✅ proper use of the Verhoeff algorithm to validate Aadhaar numbers, with some extra safeguards added on top. The tables d, p, and inv provide the core math that the checksum relies on, while helper functions like invArray, generate, and validate handle converting the input and running the algorithm. The main function checkAadhaarErrors 🪪 goes further by checking for common mistakes: it makes sure the number is exactly 12 digits, rejects trivial patterns like 111111111111 or 123456789012, and then uses Verhoeff to spot possible typing errors. The return value is a structured object with flags and messages 🔎, so developers can easily show users what went wrong. Overall, this code is solid for frontend or backend validation, helping catch fake inputs, typos, and invalid Aadhaar numbers before they hit your system 🚀.

[itzdheerajsingh]

The code you shared is an Aadhaar error detection utility that uses the Verhoeff algorithm for checksum validation.
Let me break it down for you step by step:

🔹 Key Components

1)(Multiplication Table):
Part of the Verhoeff algorithm. It defines how digits combine in the checksum calculation.

2. (Permutation Table):
   Another piece of Verhoeff – ensures positions of digits matter when computing the checksum.
   inv (Inverse Table):
   Used to finalize and validate the checksum.

3)invArray() Function:
Converts input (string/number) → array of digits.
Reverses the digits (important in Verhoeff).

4)generate() Function:
Generates a checksum digit for a given number.
Useful when creating numbers that must pass Verhoeff validation.

5)validate() Function:
Runs the Verhoeff checksum.
Returns true if the number passes (valid), false otherwise.

🔹 Aadhaar-specific Logic

checkAadhaarErrors(aadhaarNumber) does multiple checks:
Input validation
Must be a string.
Remove non-digits.
Length check
Aadhaar must be 12 digits.
Obvious fake values
Rejects all-same digits (111111111111, 000000000000, etc).
Rejects sequences like 123456789012.
Checksum verification
Uses Verhoeff validation (the same algorithm Aadhaar uses).
If checksum fails, assumes it’s a typing error.

[AdamKowalczuk]

Yes, its correct

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