I have an array of strings which when I iterate through and print its elements gives me unexpected results.
char currencies[][3] = {"EUR", "GBP", "USD", "JPY", "CNY"};
void show_currencies()
{
int i;
for(i=0; i<5; i++)
{
printf("%s - ", currencies[i]);
}
}
when I call show_currencies() I get this on output.
EURGBPUSDJPYCNY - GBPUSDJPYCNY - USDJPYCNY - JPYCNY - CNY -
Can anyone explain this behaviour.
Thank you
You are missing the nul terminators the strings are actually 4 characters long. Each string is then over writing the previous string's null terminator*. Try instead:
char currencies[][4] = {"EUR", "GBP", "USD", "JPY", "CNY"};
*As pointed out by caf it is not "over writing the previous string's null terminator" as the null terminator is never copied into the array. It is a fluke that the string is does not have garbled output after the final '-'.
You're declaring it wrong. This will work. It just lets the compiler set up an array of pointers-to-const-chars:
const char *currencies[] = {"EUR", "GBP", "USD", "JPY", "CNY"};
EDIT: Making it a two-dimension array, like Charles Beattie's answer, works too, provided you allocate space for the null. Also, specify that chars are const, per Christoph.
const qualifiers, though
You don't have an array of strings but an array of array-of-char. You could use:
char* currencies[] = {"EUR", "GBP", "USD", "JPY", "CNY"}; // untested
to allow for strings of different lengths.
Change
char currencies[][3]
to
char currencies[][4]
strings in C are NULL terminated, to make their handling (in printing, copying etc) easier.
example: char str[] = "ABC";
will declare a string of 4 char with \0 as the last char (index 3).
As a tip whenever on printing a char array you get unexpected results you might wanna check to see if the char array is NULL terminated or not.
Sure. "EUR" is four characters long - three for the letters, one for the terminating null character. Since you're explicitly specifying three-character arrays, the compiler is truncating, and so your data is strung together. You're lucky there is apparently a zero character at the end of the array, or you could get all sorts of garbage. Change your declaration to char currencies[][4].
My C is quite rusty, but try:
char currencies[][3] = {"EUR\0", "GBP\0", "USD\0", "JPY\0", "CNY\0"};
I'm just curious to know what happens
"EUR\0" is equiv {'E','U','R','\0','\0'}