Method is called automatically on object creation?

Question

I can't understand the output of this code.

The class;

public class StaticMethodClass {

  public String str = display();

  public static String display() {
    System.out.println("Static Method");
    return "Hello";
  }

}

The main;

public static void main(String[] args) {
    System.out.println("Main");
    StaticMethodClass methodClass = new StaticMethodClass();
    System.out.println(methodClass.str);
  }

Output;

Main
Static Method
Hello

Why is display() method called automatically?

Answer 1

When you create an instance of the class it will need to initialize all the fields. Hence, the display() method is called to initialize "str" .

Answer 2

因为，您在类的实例处调用了display方法。

public String str = display();

Answer 3

创建新的StaticMethodClass时，它将通过调用display（）初始化str。

Answer 4

Because class member str is initialized with this method upon creation of object of class StaticMethodClass . You create an object in the main() method.