With this example we are going to demonstrate how to make static values initialization in classes. In short, to make static values initialization in classes we have followed the steps below:
- We have created a class
Awith a methodfunction1(int i). - We have also created class
B, that has two staticAfields,b1andb2. In its constructor it callsfunction1(int i)ofA b2field. It also has a methodfunction2(int i). - Another class we have created is
C, that has a fieldA b3, and twostaticfieldsA b4andA b5. In its constructor it callsfunction1(int i)ofA b4field and it also has a methodfunction3(int i). - In
StaticInitialclass, we have astatic B t2field that is initialized usingB()constructor. First its twostaticfields are initialized and then inB()constructorfunction1()is called. - In
StaticInitialclass anotherstaticfield is initialized, that isC t3. All static fields ofCare initialized, and then the nonstaticfield is initialized and the constructor is called, that invokesfunction1()method ofA. - A
main()method inStaticInitialis called, where we create a new instance ofCclass. Its non static field is initialized and then its constructor is called, that callsfunction1().
Let’s take a look at the code snippet that follows:
package com.javacodegeeks.snippets.core;
class A {
A(int i) {
System.out.println("A(" + i + ")");
}
void function1(int i) {
System.out.println("function1(" + i + ")");
}
}
class B {
static A b1 = new A(1);
B() {
System.out.println("B()");
b2.function1(1);
}
void function2(int i) {
System.out.println("function2(" + i + ")");
}
static A b2 = new A(2);
}
class C {
A b3 = new A(3);
static A b4 = new A(4);
C() {
System.out.println("Cupboard()");
b4.function1(2);
}
void function3(int i) {
System.out.println("function3(" + i + ")");
}
static A b5 = new A(5);
}
public class StaticInitial {
public static void main(String[] args) {
System.out.println("Creating new C() in main");
new C();
System.out.println("Creating new C() in main");
new C();
t2.function2(1);
t3.function3(1);
}
static B t2 = new B();
static C t3 = new C();
}
Output:
A(1)
A(2)
B()
function1(1)
A(4)
A(5)
A(3)
Cupboard()
function1(2)
Creating new C() in main
A(3)
Cupboard()
function1(2)
Creating new C() in main
A(3)
Cupboard()
function1(2)
function2(1)
function3(1)
This was an example of how to make static values initialization in classes in Java.
