7 replies to this topic

[csepraveenkumar]

is it possible to initialise a char array separately from where it is declared without using either a for loop or initialising the array character by character?

[eafkuor]

char *str;


str = "hello";

[Alexander]

Here are some of varying levels of usefulness and complexity:

char foo1[] = "abc";                         //automatically define null ending
char foo2[4] = "abc\0";                    //manually define it
char foo3[4] = {'a', 'a' + 1, 'c', 0}; //automatic conversion to chars, then char array
printf("%s, %s, %s\n", foo1, foo2, foo3);

The third one works because ASCII 'a' + 1 is ASCII 'b', and 0 is the same as char \0 (but not '0')

[csepraveenkumar]

Alexander said:

Here are some of varying levels of usefulness and complexity:

char foo1[] = "abc";                         //automatically define null ending
char foo2[4] = "abc\0";                    //manually define it
char foo3[4] = {'a', 'a' + 1, 'c', 0}; //automatic conversion to chars, then char array
printf("%s, %s, %s\n", foo1, foo2, foo3);

The third one works because ASCII 'a' + 1 is ASCII 'b', and 0 is the same as char \0 (but not '0')

in this example all the arrays are initialised where they are declared. what if i want to initialise a char array some place other than where i declare it without using for loop.

[gregwarner]

Use strncpy()

char[10] str;

...

strncpy(str, "Hello", 10);

Just be sure to include string.h

[Alexander]

The most simple way is to access it as a pointer, an example showing this:

  char somestring[32];
  char *ptr = somestring;
  if(!ptr) {
    fprintf(stderr, "Pointing to NULL buffer");
  } 
  strncpy(ptr, "foobar\0", sizeof(somestring));

[rocketboy9000]

WARNING:
gregwarner wrote:

char[10] str;

This is not valid C, it is Java. In C, the array type specifier has the same syntax, precedence and notation as the array subscript operator.

char str[10];

[gregwarner]

So sorry about that. You're absolutely right. I code in Java at work, and with my head in the Java clouds all day long, it's easy to accidentally cross between the two languages. Good spotting my mistake. :)