Example: String to Lowercase using tolower() in C

C
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// String to Lowercase using tolower()
#include <stdio.h>
#include <string.h> // For strlen
#include <ctype.h>  // For tolower

void toLowerCase(char *str) {
    // Step 1: Iterate through the string until the null terminator is found.
    for (int i = 0; str[i] != '\0'; i++) {
        // Step 2: Use tolower() to convert the character to lowercase.
        // tolower() returns the lowercase equivalent if it's an uppercase letter,
        // otherwise, it returns the character itself unchanged.
        str[i] = tolower((unsigned char)str[i]);
    }
}

int main() {
    char myString[] = "HELLO, WORLD! 123";

    printf("Original string: %s\n", myString);

    // Step 3: Call the toLowerCase function.
    toLowerCase(myString);

    printf("Lowercase string: %s\n", myString);

    return 0;
}