Class Luhn

Namespace

LuhnDotNet

Assembly

LuhnDotNet.dll

A C# implementation of the Luhn algorithm.

public static class Luhn

Inheritance

object

Luhn

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Methods

ComputeLuhnCheckDigit(ReadOnlySpan<char>)

Computes the Luhn check digit

public static byte ComputeLuhnCheckDigit(this ReadOnlySpan<char> number)

Parameters

number ReadOnlySpan<char>

An identification number w/o check digit.

Returns

byte

The calculated Luhn check digit.

Exceptions

ArgumentException

number is not valid. It contains none-numeric characters.

ComputeLuhnCheckDigit(string)

Computes the Luhn check digit.

public static byte ComputeLuhnCheckDigit(this string number)

Parameters

number string

An identification number w/o check digit.

Returns

byte

The calculated Luhn check digit as a byte.

Exceptions

ArgumentException

number is not valid. It contains none-numeric characters.

ComputeLuhnNumber(ReadOnlySpan<char>)

Computes the Luhn number, which is a combination of the given number and the calculated check digit.

public static string ComputeLuhnNumber(this ReadOnlySpan<char> number)

Parameters

number ReadOnlySpan<char>

An identification number w/o check digit.

Returns

string

The calculated Luhn number.

Exceptions

ArgumentException

number is not valid. It contains none-numeric characters.

ComputeLuhnNumber(string)

Computes the Luhn number, which is a combination of the given number and the calculated check digit.

public static string ComputeLuhnNumber(this string number)

Parameters

number string

An identification number w/o check digit.

Returns

string

The calculated Luhn number.

Exceptions

ArgumentException

number is not valid. It contains none-numeric characters.

ConvertAlphaNumericToNumeric(string)

Converts an alphanumeric string to a numeric string.

public static string ConvertAlphaNumericToNumeric(this string alphaNumeric)

Parameters

alphaNumeric string

The alphanumeric string to convert.

Returns

string

A numeric string where each letter in the input string is replaced by its decimal ASCII value minus 55.

Remarks

This method iterates over each character in the input string. If the character is a letter, it is replaced by its decimal ASCII value minus 55. If the character is a digit, it is left unchanged.

Exceptions

ArgumentException

The alphaNumeric contains a character that is neither a letter nor a digit.

IsValid(ReadOnlySpan<char>)

Checks whether the Luhn Number is valid

[Obsolete("Use the IsValidLuhnNumber method instead.", false)]
public static bool IsValid(this ReadOnlySpan<char> luhnNumber)

Parameters

luhnNumber ReadOnlySpan<char>

An identification number w/ check digit (Luhn Number).

Returns

bool

true if the luhnNumber is valid; otherwise false

Remarks

The check digit must be at the end of the luhnNumber (on the right side).

Exceptions

ArgumentException

luhnNumber is not valid. It contains none-numeric characters.

IsValid(ReadOnlySpan<char>, byte)

Checks whether the concatenation of number and corresponding Luhn check digit is valid

[Obsolete("Use the IsValidLuhnCheckDigit method instead.", false)]
public static bool IsValid(this ReadOnlySpan<char> number, byte checkDigit)

Parameters

number ReadOnlySpan<char>

Identification number w/o Luhn check digit

checkDigit byte

The Luhn check digit

Returns

bool

true if the number is valid; otherwise false

Exceptions

ArgumentException

number is not valid. It contains none-numeric characters.

ArgumentOutOfRangeException

The checkDigit value is greater than 9. The checkDigit value must be between 0 and 9.

IsValid(string)

Checks whether the Luhn Number is valid

[Obsolete("Use the IsValidLuhnNumber method instead.", false)]
public static bool IsValid(this string luhnNumber)

Parameters

luhnNumber string

An identification number w/ check digit (Luhn Number).

Returns

bool

true if the luhnNumber is valid; otherwise false

Remarks

The check digit must be at the end of the luhnNumber (on the right side).

Exceptions

ArgumentException

luhnNumber is not valid. It contains none-numeric characters.

IsValid(string, byte)

Checks whether the concatenation of number and corresponding Luhn check digit is valid

[Obsolete("Use the IsValidLuhnCheckDigit method instead.", false)]
public static bool IsValid(this string number, byte checkDigit)

Parameters

number string

Identification number w/o Luhn check digit

checkDigit byte

The Luhn check digit

Returns

bool

true if the number is valid; otherwise false

Exceptions

ArgumentException

number is not valid. It contains none-numeric characters.

ArgumentOutOfRangeException

The checkDigit value is greater than 9. The checkDigit value must be between 0 and 9.

IsValidLuhnCheckDigit(byte, ReadOnlySpan<char>)

Checks whether the concatenation of number and corresponding Luhn check digit is valid

public static bool IsValidLuhnCheckDigit(this byte checkDigit, ReadOnlySpan<char> number)

Parameters

checkDigit byte

The Luhn check digit

number ReadOnlySpan<char>

Identification number w/o Luhn check digit

Returns

bool

true if the number is valid; otherwise false

Exceptions

ArgumentException

number is not valid. It contains none-numeric characters.

ArgumentOutOfRangeException

The checkDigit value is greater than 9. The checkDigit value must be between 0 and 9.

IsValidLuhnCheckDigit(byte, string)

Checks whether the concatenation of number and corresponding Luhn check digit is valid

public static bool IsValidLuhnCheckDigit(this byte checkDigit, string number)

Parameters

checkDigit byte

The Luhn check digit

number string

Identification number w/o Luhn check digit

Returns

bool

true if the number is valid; otherwise false

Exceptions

ArgumentException

number is not valid. It contains none-numeric characters.

ArgumentOutOfRangeException

The checkDigit value is greater than 9. The checkDigit value must be between 0 and 9.

IsValidLuhnNumber(ReadOnlySpan<char>)

Checks whether the Luhn Number is valid

public static bool IsValidLuhnNumber(this ReadOnlySpan<char> luhnNumber)

Parameters

luhnNumber ReadOnlySpan<char>

An identification number w/ check digit (Luhn Number).

Returns

bool

true if the luhnNumber is valid; otherwise false

Remarks

The check digit must be at the end of the luhnNumber (on the right side).

Exceptions

ArgumentException

luhnNumber is not valid. It contains none-numeric characters.

IsValidLuhnNumber(string)

Checks whether the Luhn Number is valid

public static bool IsValidLuhnNumber(this string luhnNumber)

Parameters

luhnNumber string

An identification number w/ check digit (Luhn Number).

Returns

bool

true if the luhnNumber is valid; otherwise false

Remarks

The check digit must be at the end of the luhnNumber (on the right side).

Exceptions

ArgumentException

luhnNumber is not valid. It contains none-numeric characters.