Utility Functions and C Language Reference > C Language Reference > Alphabetical List of Functions > isdigit


Example: isdigit Character Classification and Conversion Functions

Checks if a string is a decimal digit (characters `0' to `9').

int isdigit( int c );

c The string to check.

For isdigit details, refer to your C language documentation.

Return Values

This function returns a non-zero value (true) if the character is a decimal digit, zero (false) if it is not.