方法重载的参数为基本类型

1. 基本类型从一个较小的类型自动提升到一个较大的类型。

package example4;

import org.junit.Test;

/*
 * @className PrimitiveOverloading
 * @author HowardAllen
 * @date 2018年7月29日 上午10:17:40
 * @Description 
 *
 */

public class PrimitiveOverloading {
	
	void f1(char x){System.out.print("f1(char)");}
	void f1(byte x){System.out.print("f1(byte)");}
	void f1(short x){System.out.print("f1(short)");}
	void f1(int x){System.out.print("f1(int)");}
	void f1(long x){System.out.print("f1(long)");}
	void f1(float x){System.out.print("f1(float)");}
	void f1(double x){System.out.print("f1(double)");}
	
	void f2(byte x){System.out.print("f2(byte)");}
	void f2(short x){System.out.print("f2(short)");}
	void f2(int x){System.out.print("f2(int)");}
	void f2(long x){System.out.print("f2(long)");}
	void f2(float x){System.out.print("f2(float)");}
	void f2(double x){System.out.print("f2(double)");}
	
	void f3(short x){System.out.print("f3(short)");}
	void f3(int x){System.out.print("f3(int)");}
	void f3(long x){System.out.print("f3(long)");}
	void f3(float x){System.out.print("f3(float)");}
	void f3(double x){System.out.print("f3(double)");}
	
	void f4(int x){System.out.print("f4(int)");}
	void f4(long x){System.out.print("f4(long)");}
	void f4(float x){System.out.print("f4(float)");}
	void f4(double x){System.out.print("f4(double)");}
	
	void f5(long x){System.out.print("f5(long)");}
	void f5(float x){System.out.print("f5(float)");}
	void f5(double x){System.out.print("f5(double)");}
	
	void f6(float x){System.out.print("f6(float)");}
	void f6(double x){System.out.print("f6(double)");}
	
	void f7(double x){System.out.print("f7(double)");}
	
	@Test
	public void testCinstVal(){
		f1(5);
		f2(5);
		f3(5);
		f4(5);
		f5(5);
		f6(5);
		f7(5);
	}
	// output: f1(int)f2(int)f3(int)f4(int)f5(long)f6(float)f7(double)
	// 因为默认整型为int
	
	@Test
	public void testChar(){
		char a = 'H';
		f1(a);
		f2(a);
		f3(a);
		f4(a);
		f5(a);
		f6(a);
		f7(a);
	}
	// output: f1(char)f2(int)f3(int)f4(int)f5(long)f6(float)f7(double)
	// 系统默认将char转为int
	
	@Test
	public void testByte(){
		byte a = 20;
		f1(a);
		f2(a);
		f3(a);
		f4(a);
		f5(a);
		f6(a);
		f7(a);
	}
	// output: f1(byte)f2(byte)f3(short)f4(int)f5(long)f6(float)f7(double)
	
	@Test
	public void testShort(){
		short a = 20;
		f1(a);
		f2(a);
		f3(a);
		f4(a);
		f5(a);
		f6(a);
		f7(a);
	}
	// output: f1(short)f2(short)f3(short)f4(int)f5(long)f6(float)f7(double)
	
	@Test
	public void testInt(){
		int a = 20;
		f1(a);
		f2(a);
		f3(a);
		f4(a);
		f5(a);
		f6(a);
		f7(a);
	}
	// output: f1(int)f2(int)f3(int)f4(int)f5(long)f6(float)f7(double)
	
	@Test
	public void testLong(){
		long a = 20;
		f1(a);
		f2(a);
		f3(a);
		f4(a);
		f5(a);
		f6(a);
		f7(a);
	}
	// output: f1(long)f2(long)f3(long)f4(long)f5(long)f6(float)f7(double)
	
	@Test
	public void testFolat(){
		float a = 20F;
		f1(a);
		f2(a);
		f3(a);
		f4(a);
		f5(a);
		f6(a);
		f7(a);
	}
	// output: f1(float)f2(float)f3(float)f4(float)f5(float)f6(float)f7(double)
	
	@Test
	public void testDouble(){
		double a = 20F;
		f1(a);
		f2(a);
		f3(a);
		f4(a);
		f5(a);
		f6(a);
		f7(a);
	}
	// output: f1(double)f2(double)f3(double)f4(double)f5(double)f6(double)f7(double)
}

2. 基本类型是一个较大的类型时，必须强制转换，否则无法通过编译。