Question

How to convert a character inside string to lowercase in C

Answer 1

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

void char_to_lowercase(char s[], int idx) { 
    if (idx < 0 || idx > strlen(s)) return;
           
    for (int i = 0; i < strlen(s); i++) {
         if (i == idx) {
             s[i] = tolower(s[i]);
         }
    }
}
int main() 
{                       
    char s[] = "C PROGRAMMING"; 
   
	char_to_lowercase(s, 3);
    puts(s);
    
    char_to_lowercase(s, 0);
    puts(s);
     
    char_to_lowercase(s, strlen(s) - 1);
    puts(s);
	
    return 0; 
} 
 
 
 
/*
run:
 
C PrOGRAMMING
c PrOGRAMMING
c PrOGRAMMINg
 
*/

 

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