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## Problem

You want to find hexadecimal numbers in a larger body of text, or check whether a string variable holds a hexadecimal number.

## Solution

Find any hexadecimal number in a larger body of text:

`\b[0-9A-F]+\b`
 Regex options: Case insensitive Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python, Ruby
`\b[0-9A-Fa-f]+\b`
 Regex options: None Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python, Ruby

Check whether a text string holds just a hexadecimal number:

`\A[0-9A-F]+\Z`
 Regex options: Case insensitive Regex flavors: .NET, Java, PCRE, Perl, Python, Ruby
`^[0-9A-F]+\$`
 Regex options: Case insensitive Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python

Find a hexadecimal number with a `0x` prefix:

`\b0x[0-9A-F]+\b`
 Regex options: Case insensitive Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python, Ruby

Find a hexadecimal number with an `&H` prefix:

`&H[0-9A-F]+\b`
 Regex options: Case insensitive Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python, Ruby

Find a hexadecimal number with an `H` suffix:

`\b[0-9A-F]+H\b`
 Regex options: Case insensitive Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python, Ruby

Find a hexadecimal byte value or 8-bit number:

`\b[0-9A-F]{2}\b`
 Regex options: Case insensitive Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python, Ruby

Find a hexadecimal word value or 16-bit number:

`\b[0-9A-F]{4}\b`
 Regex options: Case insensitive Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python, Ruby

Find a hexadecimal double word value or 32-bit number:

`\b[0-9A-F]{8}\b ...`

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