C language deletes the last character of a string

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

int main()
{
    char str[30] = "hello lautturi world";
    str[strlen(str)-1] = '\0';
    printf("%s",str);
    return 0;
}

output:

hello lautturi worl
Process returned 0 (0x0)   execution time : 0.259 s