Non-static methods are the "normal" type of methods for a class to have. They use instance variables to perform certain actions. In other words, object A and object B of the same class may behave differently when we call one of their Non-static methods depending on the value of their instance variables. Static methods on the other hand behave the exact same way for all instances of a class. object A and B of the same class will act in the same way when we call one of their Static methods. (*NOTE* Static methods cannot use instance variables)
A static method in java is also named a class method, because it does not need an instance (of his class) to be invoked. Static methods can't use instance variables (non static variables) or use the keywords 'this'. These methods receive all the information they need to complete his task from his parameters
I assume the question is about Java. How you call a method from inside the main method depends on whether this is an instance method or a static method. To call an instance method, you need to have a valid instance. Say foo is an instance of class Foo, which was created inside the main method. Then to call the instance method implode() use foo.implode() To call the static method bar() of class Foo, use Foo.bar().
No. You will get compilation errors. The complier will complain that you are trying to access non static variables from inside a static method. A static method can access only static variables.
Static methods are not specific to each instance of a class. This allows you to have functions which return the same output for the same input for each instance of the class.
It depends on whether the member is a static variable or a static method of the class.A non-static member variable is an instance variable. That is, each instance of the class has its own independent set of instance variables.A static member variable is not associated with any one instance of the class, and exists even when there are no instances of the class. As with all static variables, it exists for the entire duration of the program.A non-static member method is an instance method, thus the method automatically inherits a this pointer.A static member method does not inherit a this pointer, but it does have private access to to the class. Thus specific instances can be passed to a static method if necessary.Static members can be thought of as being common to all instances of a class, rather than a specific instance, even though no instances are actually required in order to make use of them.
Instance methods can be called by the object of a Class whereas static method are called by the Class. When objects of a Class are created, they have their own copy of instance methods and variables, stored in different memory locations. Static Methods and variables are shared among all the objects of the Class, stored in one fixed location in memory.Static methods cannotaccess instance variables or instance methods directly-they must use an object reference. Also, class methods cannot use the this keyword as there is no instance for this to refer to.
static: we can use the keyword static either to method or to a variable. when we declare to a method,(eg: public static void main(String args[]),we can use this method without any object. when we use to a variable,there will be only one instance of that variable irrespective of how many objects that get created of that class. Final: Usage of final to method or to a variable makes them as constant. It's value cannot be changed...
== == Static method cannot be overwritten because it belongs to the class and not to the ObjectIf you're asking about overriding or overloading, then yes. Static methods can be overridden and overloaded just like any other methods.
The main method is called by the jvm when your program is executed. The main method is a static method: public static void main(String[] args) {} A static method is method that can be run without instantiate the class (creating an object from it) The main method is a static method. No other static method could replace it's functionality. PS By static method do you mean static initialiser? I often use static initialisers instead of a main method, but in these cases you must still have a main method, albeit an empty one ie. public static void main(String[] args) {} Notice that the method has an empty body A main method must be used if you intend to accept parameters at run time from the jvm.
No. Static methods are invoked by using the name of the class instead of the name of an instance of a class. Example: public class Test { public static void methodA { // do something ... } public void methodB { // do something else ... } } A program could use methodA by simply calling it using the class name: // call the static method Test.methodA(); To use methodB(), a program would have to first create an instance of the class then call the method: // call the non-static method Test t = new Test(); t.methodB(); Note that you can call methodA from the instance: // call the static method Test t = new Test(); t.methodA(); However, this is considered bad practice. And you cannot call methodB at all using the class name: // can't do this - compile error Test.methodB();
They can't be. If you want to use a non-static field in a static method, you need an instance of the class to reference. class MyClass { int myX; static int staticX; public static void main(String[] args) { // We can directly reference staticX whenever we want. staticX = 10; // We need an instance of MyClass to use myX. MyClass mc = new MyClass(); mc.myX = 10; } }
Shortly, you can not.Different approaches are however available.1. Put your non static method in different class. Then call it from your static content by first instantiating the class.2. Make a duplicate static method for your non static method and use from your static content.