# isxdigit

isxdigit(c::Union{Char,AbstractString}) -> Bool

Tests whether a character is a valid hexadecimal digit, or whether this is true for all elements of a string.

## Examples

``````julia> isxdigit('A')
true

julia> isxdigit('9')
true

julia> isxdigit('G')
false

julia> isxdigit("abc123")
true

julia> isxdigit("123!")
false``````

The `isxdigit` function in Julia is used to test whether a character is a valid hexadecimal digit. It can also be used to check if all characters in a string are valid hexadecimal digits.

The function returns `true` if the character or all characters in the string are valid hexadecimal digits, and `false` otherwise.

Common examples of its use include:

1. Check if a character is a valid hexadecimal digit:

``````julia> isxdigit('A')
true``````

This example checks if the character 'A' is a valid hexadecimal digit. Since 'A' is indeed a valid hexadecimal digit, the function returns `true`.

2. Check if a character is a valid hexadecimal digit:

``````julia> isxdigit('9')
true``````

Here, the function checks if the character '9' is a valid hexadecimal digit. Since '9' is a valid hexadecimal digit, the function returns `true`.

3. Check if a character is a valid hexadecimal digit:

``````julia> isxdigit('G')
false``````

In this example, the function checks if the character 'G' is a valid hexadecimal digit. Since 'G' is not a valid hexadecimal digit, the function returns `false`.

4. Check if all characters in a string are valid hexadecimal digits:

``````julia> isxdigit("abc123")
true``````

Here, the function checks if all characters in the string "abc123" are valid hexadecimal digits. Since all the characters in the string are valid hexadecimal digits, the function returns `true`.

5. Check if all characters in a string are valid hexadecimal digits:

``````julia> isxdigit("123!")
false``````

This example checks if all characters in the string "123!" are valid hexadecimal digits. Since '!' is not a valid hexadecimal digit, the function returns `false`.

Note: The `isxdigit` function can also be used with characters and strings in other languages, as long as the character encoding supports hexadecimal digits.