Question

To make a string a null string i wrote this:

#include<stdio.h>
#include<conio.h>
#include<string.h>
int main()
{
    char str[15]="fahad uddin";
    strlen(str);
    puts(str);
    for(int i=0;str[i]!='\0';i++)
        strcpy(&str[i],"\0") ;
    puts(str);
    getch();
    return 0;
}

Before this i tried:

#include<stdio.h>
#include<conio.h>
#include<string.h>
int main()
{
    char str[15]="fahad uddin";
    strlen(str);
    puts(str);
    for(int i=0;str[i]!='\0';i++,strcpy(&str[i],"\0"))
        ;
    puts(str);
    getch();
    return 0;
}

In the first example, the program runs all right while when in the second example it prints the first letter of the string (in this example F). Why is this?

Answer 1

C strings are null-terminated. As long as you only use the functions assuming null-terminated strings, you could just zero the first character.

str[0] = '\0';