# isxdigit() function in C Language

isxdigit() function in C programming language checkes that whether the given character is hexadecimal or not. isxdigit() function is defined in ctype.h header file.

Hexadecimal equivalent of Decimal Numbers:

```Hexadecimal: 0   1   2   3    4   5    6   7    8   9    A    B       C      D    E     F
Decimal:    0   1    2   3    4   5    6   7    8   9    10   11    12     13    14    15
```

Syntax:

```char isxdigit( char x);
```

Examples:

```Input : A
Output : Entered character is hexadecimal
Input : 2
Output : Entered character is hexadecimal
Input : @
Output : Entered character is not hexadecimal
```
```// C program to demonstrate isxdigit()
#include <ctype.h>
#include <stdio.h>

int main()
{
// taking input
char ch = 'A';

// checking is the given input is hexadecimal or not?
if (isxdigit(ch))
printf("\nEntered character is hexadecimal");
else
printf("\nEntered character is not hexadecimal");
}
```

Output:

```Entered character is hexadecimal
```

Application : isxdigit() function in C programming language is used to find out total numbers of hexadecimals present in any given input.
Example:

```Input: abc123
Output: Number of hexadecimals present in the given input is : 6
Input: abcdef
Output: Number of hexadecimals present in the given input is : 6
Input: 123456@\$
Output: Number of hexadecimals present in the given input is : 6
```

Let’s see C program on this topic:

```// C program to demonstrate isxdigit()
#include <ctype.h>
#include <stdio.h>

int ttl_hexadecimal(int i, int counter)
{
char ch;
char a[50] = "@#asf12345";
ch = a[0];

// counting of hexadecimal numbers
while (ch != '\0') {
ch = a[i];
if (isxdigit(ch))
counter++;

i++;
}

// returning total number of hexadecimal
// in the given input
return (counter);
}

int main()
{
int i = 0;
int counter = 0;
counter = ttl_hexadecimal(i, counter);

printf("\nNumber of hexadecimals in string"
" is : %d", counter);
return 0;
}
```

Output:

`Number of hexadecimals in string is : 7`

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