C Language Basics – Using Function Pointer Arrays for String Cleaning

#include <stdio.h>
#include <string.h>
#include <ctype.h>
typedef void (*funcPtr)(char *);
// 1. Remove leading and trailing whitespace (similar to Python's strip)
void trim(char *str) {
    int i = 0, j;
    int len = strlen(str);
    // Remove leading whitespace
    while (isspace(str[i])) i++;
    // Remove trailing whitespace
    j = len - 1;
    while (j >= 0 && isspace(str[j])) j--;
    if (j < i) {
        str[0] = '\0';
        return;
    }
    memmove(str, str + i, j - i + 1);
    str[j - i + 1] = '\0';
}
// 2. Remove specified punctuation (!#?)
void remove_punctuation(char *str) {
    int i = 0, j = 0;
    while (str[i]) {
        if (str[i] != '!' && str[i] != '#' && str[i] != '?') {
            str[j++] = str[i];
        }
        i++;
    }
    str[j] = '\0';
}
// 3. Implement title case (similar to Python's title)
void title_case(char *str) {
    int new_word = 1;
    for (int i = 0; str[i]; i++) {
        if (isalpha(str[i])) {
            if (new_word) {
                str[i] = toupper(str[i]);
                new_word = 0;
            } else {
                str[i] = tolower(str[i]);
            }
        } else {
            new_word = 1;
        }
    }
}
int main() {
    char input[] = "  !HellO ###woRld!!!  "; // Test input
    // Define function pointer array
    funcPtr funcArray[3] = {
        trim,
        remove_punctuation,
        title_case
    };
    for(int i=0;i<3;i++){
        funcArray[i](input);
    }
    printf("Cleaned result: \"%s\"\n", input);
    return 0;
}

Cleaned result: "Hello World"

Below is the Python code implementation

import re
def remove_punctuation(value):
    return re.sub("[!#?]", "", value)
clean_ops = [str.strip, remove_punctuation, str.title]  # Remove leading and trailing spaces, remove special characters, format camel case words
result = []
def clean_string(value):
    for func in clean_ops:
        value = func(value)
        result.append(value)
    return result
print(clean_string("   !HellO ###woRld!!!   "))

['!HellO ###woRld!!!', 'HellO woRld', 'Hello World']