Use RETURNS void like below: CREATE FUNCTION stamp_user(id int, comment text) RETURNS void AS $$ #variable_conflict use_variable DECLARE curtime timestamp := now(); BEGIN UPDATE users SET last_modified = curtime, comment = comment WHERE users.id = id; END; $$ LANGUAGE plpgsql;
I just did some tests of the four options that I know about. Measure-Command {$(1..1000) | Out-Null} TotalMilliseconds : 76.211 Measure-Command {[Void]$(1..1000)} TotalMilliseconds : 0.217 Measure-Command {$(1..1000) > $null} TotalMilliseconds : 0.2478 Measure-Command {$null = $(1..1000)} TotalMilliseconds : 0.2122 ## Control, times vary from 0.21 to 0.24 Measure-Command {$(1..1000)} TotalMilliseconds : 0.2141 So I would … Read more
Void has become convention for a generic argument that you are not interested in. There is no reason why you should use any other non-instantiable type, such as System. It is also often used in for example Map values (although Collections.newSetFromMap uses Boolean as maps don’t have to accept null values) and java.security.PrivilegedAction.
If a method doesn’t return anything, it’s either one of the following imperative – You’re either asking the object to do something to itself.. e.g change state (without expecting any confirmation.. its assumed that it will be done) informational – just notifying someone that something happened (without expecting action or response) respectively. Imperative methods – … Read more
This is straight from PEP 484 — Type Hints documentation: When used in a type hint, the expression None is considered equivalent to type(None). And, as you can see most of the examples use None as return type.
void foo(void); That is the correct way to say “no parameters” in C, and it also works in C++. But: void foo(); Means different things in C and C++! In C it means “could take any number of parameters of unknown types”, and in C++ it means the same as foo(void). Variable argument list functions … Read more
Use Supplier if it takes nothing, but returns something. Use Consumer if it takes something, but returns nothing. Use Callable if it returns a result and might throw (most akin to Thunk in general CS terms). Use Runnable if it does neither and cannot throw.
All the other answers are correct, but just for completion A function is declared in the following manner: return-type function-name(parameter-list,…) { body… } return-type is the variable type that the function returns. This can not be an array type or a function type. If not given, then int is assumed. function-name is the name of … Read more
Take a look at the Mockito API docs. As the linked document mentions (Point # 12) you can use any of the doThrow(),doAnswer(),doNothing(),doReturn() family of methods from Mockito framework to mock void methods. For example, Mockito.doThrow(new Exception()).when(instance).methodName(); or if you want to combine it with follow-up behavior, Mockito.doThrow(new Exception()).doNothing().when(instance).methodName(); Presuming that you are looking at … Read more
The void operator evaluates the given expression and then returns undefined. The void operator is often used merely to obtain the undefined primitive value, usually using “void(0)” (which is equivalent to “void 0”). In these cases, the global variable undefined can be used instead (assuming it has not been assigned to a non-default value). An … Read more