Can someone explain a void return type in Java? The void type is used to declare that a method does not return a value. Couldn’t you just make the return type String and set the string equal to the parameter to make it show up when the method is called? Hypothetically “you” (or in this … Read more
Using a hyperlinked C++ grammar, the parsing of decltype(void()) is: decltype( expression ) decltype( assignment-expression ) decltype( conditional-expression ) … lots of steps involving order of operations go here … decltype( postfix-expression ) decltype( simple-type-specifier ( expression-listopt ) ) decltype( void() ) So void() is a kind of expression here, in particular a postfix-expression. Specifically, … Read more
void has special meaning in function return types, and is not an alias for undefined. Thinking of it this way is very wrong. Why? The intent of void is that a function’s return value will not be observed. This is very different from will be undefined. It’s important to have this distinction so that you … Read more
You mean the tellItLikeItIs method? Yes, you have to specify void to specify that the method doesn’t return anything. All methods have to have a return type specified, even if it’s void. It certainly doesn’t return a string – look, there are no return statements anywhere. It’s not really clear why you think it is … Read more
java.lang.Void is analogous to java.lang.Integer. Integer is a way of boxing values of the primitive type int. Void is a way of boxing values of the primitive type void. “But wait, void doesn’t have any possible values!” Right! That’s what makes java.lang.Void “uninstantiable”. 🙂 It’s a nice feature of the Java type system that every … Read more
Here is a little bit detailed explanation on why main method is declared as public static void main(String[] args) Main method is the entry point of a Java program for the Java Virtual Machine(JVM). Let’s say we have a class called Sample class Sample { static void fun() { System.out.println(“Hello”); } } class Test { … Read more
In C, the declaration int f(void) means a function returning int that takes no parameters. The declaration int f() means a function returning int that takes any number of parameters. Thus, if you have a function that takes no parameters in C, the former is the correct prototype. In C++, I believe int f(void) is … Read more
The difference is that some browsers allow you to overwrite the value of undefined. However, void anything always returns real undefined. undefined = 1; console.log(!!undefined); //true console.log(!!void 0); //false
Void is considered a data type (for organizational purposes), but it is basically a keyword to use as a placeholder where you would put a data type, to represent “no data”. Hence, you can declare a routine which does not return a value as: void MyRoutine(); But, you cannot declare a variable like this: void … Read more
When you call an async void method, or call an async Task method without awaiting it (if the called method contains an await, so it doesn’t block), your code will continue right away, without waiting for the method to actually complete. This means that several invocations of the method can be executing in parallel, but … Read more