###### (This is the documentation for SDL3, which is the current stable version. [SDL2](https://wiki.libsdl.org/SDL2/) was the previous version!) # SDL_isxdigit Report if a character is a hexadecimal digit. ## Header File Defined in [](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_stdinc.h) ## Syntax ```c int SDL_isxdigit(int x); ``` ## Function Parameters | | | | | --- | ----- | ------------------------- | | int | **x** | character value to check. | ## Return Value (int) Returns non-zero if x falls within the character class, zero otherwise. ## Remarks **WARNING**: Regardless of system locale, this will only treat ASCII values 'A' through 'F', 'a' through 'f', and '0' through '9', as true. ## Thread Safety It is safe to call this function from any thread. ## Version This function is available since SDL 3.1.3. ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryStdinc](CategoryStdinc)