is_str_num() is not handling negative numbers

[rtxa]

The is_str_num() function in string_stocks.inc currently does not handle negative numbers. The function only checks for the presence of digits in the string, without considering a leading negative sign which may be useful in some cases and that makes the function name misleading.

Updating is_str_num() may affect any existing code that relies on that behaviour, so maybe a new stock like is_str_num_ex() would be needed or a new optional parameter to allow negative numbers check. A note warning about this would be useful too.

Proposed fix

stock bool:is_str_num_ex(const sString[]) {
    new i = 0;
    new bool:is_negative = false;

    if (sString[0] == '-') {
        is_negative = true;
        i++;
    }

    while (sString[i] && isdigit(sString[i])) {
        i++;
    }

    return sString[i] == 0 && i != (is_negative ? 1 : 0);
}

Test code:

		server_print("Is str '' num? %d", is_str_num_ex(""));
		server_print("Is str '--' num? %d", is_str_num_ex("--"));
		server_print("Is str '-' num? %d", is_str_num_ex("-"));
		server_print("Is str '-0' num? %d", is_str_num_ex("-0"));
		server_print("Is str '0' num? %d", is_str_num_ex("0"));
		server_print("Is str '1000' num? %d", is_str_num_ex("1000"));
		server_print("Is str '-1000' num? %d", is_str_num_ex("-1000"));

Output:

Is str '' num? 0
Is str '--' num? 0
Is str '-' num? 0
Is str '-0' num? 1
Is str '0' num? 1
Is str '1000' num? 1
Is str '-1000' num? 1

[dvander]

Call it parse_int, make it have a bool return and optional int outparam?On Aug 7, 2024 2:08 PM, rtxa ***@***.***> wrote: The is_str_num() function in string_stocks.inc currently does not handle negative numbers. The function only checks for the presence of digits in the string, without considering a leading negative sign which may be useful in some cases and that makes the function name misleading. Updating is_str_num() may affect any existing code that relies on that behaviour, so maybe a new stock like is_str_num_ex() would be needed or a new optional parameter to allow negative numbers check. A note warning about this would be useful too. —Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[rtxa]

Call it parse_int, make it have a bool return and optional int outparam

Already exists str_to_num() but you can't rely on it because it returns 0 on failure, and the input string can be a 0, unless we check that the string first digit isn't a 0.

[fysiks1]

Call it parse_int, make it have a bool return and optional int outparam

Already exists str_to_num() but you can't rely on it because it returns 0 on failure, and the input string can be a 0, unless we check that the string first digit isn't a 0.

His suggestion solves both problems simultaneously. Conceptually:

stock bool:parse_int(szString[], &intVal = 0)
{
	if( /* If string is number */ )
	{
		intVal = str_to_num(szString)
		return true

	}
	return false
}