The wrapper class of basic data types in java is also value transfer

The packaging classes of basic data types in java are also value transfer , such as: Boolean, Integer and other packaging classes and String classes , they take value transfer , these classes can be understood as eternal immutable classes .

Directly upload the code and screenshots:

Case 1

public void handle(int parm1, Integer parm2, double parm3, Double parm4) {
		System.out.println("形参parm1=" + parm1 + ",形参parm2=" + parm2 + ",形参parm3=" + parm3 + ",形参parm4=" + parm4);
		parm1 = 12;
		parm2 = 16;
		parm3 = 27.98;
		parm4 = 168.92;
		System.out.println("形参parm1=" + parm1 + ",形参parm2=" + parm2 + ",形参parm3=" + parm3 + ",形参parm4=" + parm4);
	}

public static void main(String[] args) {
		User user = new User();

		int a = 67; //基本数据类型
		Integer b = new Integer(23); //引用数据类型
		
		double c = 92.53; //基本数据类型
		Double d = new Double(56.34); //引用数据类型
		System.out.println("实参a=" + a + ",实参b=" + b + ",实参c=" + c + ",实d=" + d);
		user.handle(a, b, c, d);
		System.out.println("实参a=" + a + ",实参b=" + b + ",实参c=" + c + ",实d=" + d);
	}

The results of the operation are as follows:

Case 2

public void handle(boolean parm1, Boolean parm2) {
		System.out.println("形参parm1=" + parm1 + ",形参parm2=" + parm2);
		parm1 = true;
		parm2 = true;
		System.out.println("形参parm1=" + parm1 + ",形参parm2=" + parm2);
	}

public static void main(String[] args) {
		User user = new User();
		
		boolean e = false; //基本数据类型
		Boolean f = new Boolean(false); //引用数据类型
		System.out.println("实参e=" + e + ",实参f=" + f);
		user.handle(e, f);
		System.out.println("实参e=" + e + ",实参f=" + f);
	}

The results of the operation are as follows: