C library functions -isdigit()
C Standard Library - <ctype.h>
Description
C Library Functionsint isdigit(int c)Checks whether the passed character is a decimal digit character.
The decimal digits are: 0 1 2 3 4 5 6 7 8 9
Declaration
Below is the declaration of the isdigit() function.
int isdigit(int c);
Parameter
- c-- This is the character to be checked.
Return Value
If c is a digit, the function returns a non-zero value; otherwise, it returns 0.
Example
The following example demonstrates the usage of the isdigit() function.
#include <stdio.h>
#include <ctype.h>
int main()
{
int var1 = 'h';
int var2 = '2';
if( isdigit(var1) )
{
printf("var1 = |%c| 是一个数字\n", var1 );
}
else
{
printf("var1 = |%c| 不是一个数字\n", var1 );
}
if( isdigit(var2) )
{
printf("var2 = |%c| 是一个数字\n", var2 );
}
else
{
printf("var2 = |%c| 不是一个数字\n", var2 );
}
return(0);
}
Let us compile and run the above program, which will produce the following result:
var1 = |h| 不是一个数字 var2 = |2| 是一个数字other extensions