靜態代碼塊

• 隨Class 加載而加載，為Class 作初始化；
• 在main() 之前加載；
• 只執行一次；

構造代碼塊

• 隨對象的創建而加載，為對象作初始化

public class day04 {
	public static day04 d1 = new day04();
	//public static day04 d2 = new day04();
	public day04(){
		System.out.println("構造方法");
	}
	
	{
		System.out.println("構造代碼塊");
	}
	static {
		System.out.println("靜態代碼塊");
	}	
	
	public static void main(String[] args) {
		System.out.println("main()");
		//day04 d = new day04();
	}
}

輸出順序：

1.構造代碼塊
2.構造方法
3.靜態代碼塊
4.main()

public class day04 {
	public static day04 d1 = new day04();
	//public static day04 d2 = new day04();
	public day04(){
		System.out.println("構造方法");
	}
	
	{
		System.out.println("構造代碼塊");
	}
	static {
		System.out.println("靜態代碼塊");
	}	
	
	public static void main(String[] args) {
		System.out.println("main()");
		day04 d = new day04();
	}
}

輸出順序：

1.構造代碼塊
2.構造方法
3.靜態代碼塊
4.main()
5.構造代碼塊
6.構造方法

main()

• 靜態代碼塊在main() 方法之前加載：

public class day04 {
	//public static day04 d1 = new day04();
	//public static day04 d2 = new day04();
	public day04(){
		System.out.println("構造方法");
	}
	
	{
		System.out.println("構造代碼塊");
	}
	static {
		System.out.println("靜態代碼塊");
	}	
	
	public static void main(String[] args) {
		System.out.println("main()");
		//day04 d = new day04();
	}
}

輸入結果：

1. 靜態代碼塊
2. main()