将字符分配给字符 *

Question

I need an entire string to be one char of another string.

const char *const_string = "FOOBAR";
char *character_string = malloc(1024);
// character_string = const_string[3];

How can I make the last (commented) line work?

Answer 1

It seems you mean the following

void do_something(char *str, int idx)
{
    str[0] = glob_str[idx];
    str[1] = '\0';
}

You can add a check to the function that the index is not outside the string literal pointed to by glob_str .

Answer 2

Given

char *glob_str = "test test";  // glob_str is literal string and cannot be modified

then

glob_str[0] = val; // modification won't work

You need to change to

char glob_str[] = "test test";

See this question