谁能解释一下这段代码的输出？

Question

char c[] = "hello"; 

printf("%*d", c);

the output is :

infinite loop of spaces

Answer 1

Can anyone explain me the output of this code?

infinite loop of spaces

char c[] = "hello";

printf("%*d", c);

the %*d say the first arg after the format indicates the width, here it is the address of c interpreted as a huge number, and the default added character to respect the width is a space.

note there is a missing arg normaly giving the value to print

---

if I use a valid code like that :

#include <stdio.h>

int main()
{
  printf("%0*d\n", 3, 1);
  return 0;
}

the result is 001 because I ask for to write '1' with a width of 3 and the added character is '0'

Answer 2

first we understand what is c[]="hello"; c is an array of char which holds hello but what is array array is pointer with chunk of memory mean above we create a array means we create a pointer whose point hello blocks memory like c means c contain adresse of first block of hello but what happened in printf("% d",c) asterisk( ) symbol represent width then first argument is width like this printf("%*c",3,c): its output is give : h here is width three and print a char which hold c :now see why screen has infinite loop let's see printf("%*d",c) as we know first argument is width of output here is a char c mean bas adress when Code executed it give adress to width and u know adress is too long and it sometime negative then why your screen have too much space not infinite because u give width as a long as a adress further doubt comment me