One use case is the singleton pattern where there can only be exactly one instance of a class. In this case, you need make your constructors and assignment operator= private so that there is no way of creating more than one object. The only way to create an object is via your GetInstance() function as … Read more
The assignment operator in Java evaluates to the assigned value (like it does in, e.g., c). So here, readLine() will be executed, and its return value stored in line. That stored value is then checked against null, and if it’s null then the loop will terminate.
In PL/PgSQL parser, assignment operator is defined as assign_operator : ‘=’ | COLON_EQUALS ; This is a legacy feature, present in source code since 1998, when it was introduced – as we can see in the PostgreSQL Git repo. Starting from version 9.4 it is oficially documented. This idiosyncrasy – of having two operators for … Read more
It’s part of a feature allowing C++11 non-static member functions to differentiate between whether they are being called on an lvalues or rvalues. In the above case, the copy assignment operator being defaulted here can only be called on lvalues. This uses the rules for lvalue and rvalue reference bindings that are well established; this … Read more
You can’t assign to an array, only copy to it. Use strcpy instead, like strcpy(word, “Jump”);
That’s the way the language was designed. It is consistent with most languages. Having a variable declaration return anything other than undefined is meaningless, because you can’t ever use the var keyword in an expression context. Having assignment be an expression not a statement is useful when you want to set many variable to the … Read more
No, they are different operators. The copy constructor is for creating a new object. It copies an existing object to a newly constructed object.The copy constructor is used to initialize a new instance from an old instance. It is not necessarily called when passing variables by value into functions or as return values out of … Read more
Why did the logical operators get left out? Is there a good technical reason why it is hard? They didn’t. You can do &= or |= or ^= if you want. bool b1 = false; bool b2 = true; b1 |= b2; // means b1 = b1 | b2 The || and && operators do … Read more
In an assignment statement, the right-hand side is always evaluated fully before doing the actual setting of variables. So, x, y = y, x + y evaluates y (let’s call the result ham), evaluates x + y (call that spam), then sets x to ham and y to spam. I.e., it’s like ham = y … Read more
First of all: that’s an interesting question, but should never come up in “real code”, as assigning to the variable you call in the very same line is confusing even if you know how it works. What happens here is these 3 steps: figure out which object to call the method on (i.e. evaluate the … Read more