strtok is part of the C library and what it does is splitting a C null-delimited string into tokens separated by any delimiter you specify. The first call to strtok must pass the C string to tokenize, and subsequent calls must specify NULL as the first argument, which tells the function to continue tokenizing the … Read more
I agree with everyone else that you should use exceptions, but if you do really need to use NULL for some reason, make the constructor private and use a factory method: static CMyClass* CMyClass::create(); This means you can’t construct instances normally though, and you can’t allocate them on the stack anymore, which is a pretty … Read more
COUNT(expr) will count the number of rows where expr is not null, thus you can count the number of nulls with expressions like these: SELECT count(a) nb_a_not_null, count(b) nb_b_not_null, count(*) – count(a) nb_a_null, count(*) – count(b) nb_b_null, count(case when a is not null and b is not null then 1 end)nb_a_b_not_null count(case when a is … Read more
Classically, compilers treated “undefined behavior” as simply an excuse not to check for various types of errors and merely “let it happen anyway.” But contemporary compilers are starting to use undefined behavior to guide optimizations. Consider this code: int table[5]; bool does_table_contain(int v) { for (int i = 0; i <= 5; i++) { if … Read more
Isn’t is bad enough that we have one null?
I just found this: The ?? operator aka the Null Coalescing Operator You also have it in C/C++ as a GNU extension using the ?: operator : string pageTitle = getTitle() ?: “Default Title”;
You can use coalesce: select account_number, coalesce(Attr1, 0) as Attr1, coalesce(Attr2, 0) as Attr2, etc
You can use reflection to iterate over the object’s field, and set them. You’d obviously need some sort of mapping between types or even field names and required default values but this can be done quite easily in a loop. For example: for (Field f : obj.getClass().getFields()) { f.setAccessible(true); if (f.get(obj) == null) { f.set(obj, … Read more
if (thing) { //your code } Is that what you are looking for?