How to Check if String contains only Numeric Digits in C - Step by Step Examples

How to Check if String contains only Numeric Digits in C ?

Answer

To check if a string contains only numeric digits in C, you can iterate through each character in the string and check if it is a digit using 'isdigit' function.

✐ Examples

1 Check if String contains only Numeric Digits using character iteration

In this example,

We create a function 'containsOnlyNumericDigits' that takes a string as input.
We iterate through each character in the string and check if it is a digit using 'isdigit' function from 'ctype.h' library.
If all characters are numeric digits, '1' is returned; otherwise, '0'.
Finally, we print the result.

C Program

#include <stdio.h>
#include <ctype.h>

int containsOnlyNumericDigits(char *str) {
  while (*str) {
    if (!isdigit(*str)) {
      return 0;
    }
    str++;
  }
  return 1;
}

int main() {
  char str[] = "12345";
  int allDigits = containsOnlyNumericDigits(str);
  printf("String contains only numeric digits: %d\n", allDigits);
  return 0;
}

Output

String contains only numeric digits: 1

Summary

In this tutorial, we learned How to Check if String contains only Numeric Digits in C language with well detailed examples.

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