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Can static variable null?
Static variable can only be null if it’s on it’s class. If you call the static variable from different class the result is NOT null.
Can you return a static variable?
Static storage duration means once the memory is allocated to person_p it will stay at the same storage location as long as program is running, allowing it to retain its value indefinitely. It means you can return a pointer to that location. Therefore, your code is valid and legal.
Which keyword should be used to declare static variables?
Explanation: The keyword used to declare static variables is static. This is must be used while declaring the static variables. The compiler can make variables static if and only if they are mentioned with static keyword.
Does a static variable have to be declared final?
Static variables are normally declared as constants using the final keyword. Constants are variables that are declared as public/private, final, and static. Constant variables never change from their initial value.
Is there a way to not return NULL in Java?
Both of these return an immutable list so the calling code should make no attempt to modify it. Java 8 introduced a class called java.util.Optional that’s designed to address the pain points associated with null values. An Optional is a container that can either be empty or contain a non-null value.
Is it necessary to set local variables to null?
Local variables hardly ever need to be set to null. There is only one exception: It may be beneficial to set local variables to null if running on a non-Microsoft CLR.
When to call public static void main in Java?
When you run “java Run”, the “public static void main” method of class Run invoke. However before this method invoked, class Run loaded and initialized. After this, the “public static void main” method call Test.display () which is a static method of class Test.
What happens if you call method on null in Java?
Pitfalls of Null. In Java, a null value can be assigned to an object reference of any type to indicate that it points to nothing. Calling a method on a null reference will throw a NullPointerException: The compiler assigns null to any uninitialized static and instance members of reference type.