public class Abc 
{ 
 private double salary; 
 public Abc(){ 
 } 
 public void ariseSalary(double em){ 
 double employ = salary * em; 
 salary += employ; 
 } 
} 

Abc a = new Abc(); 
a.ariseSalary(100); 

public void ariseSalary(double em){ 
 double employ = this.salary * em; 
 this.salary += employ; 
} 

 <span style="font-size:18px;">public class Test{ 
 private int num; 
 public void add(int b){ 
  b = a + b; 
 } 
}</span> 

<span style="font-size:18px;"> 在上面的代码中，类Test中的方法add中的形参int b就是一个显示参数，它显示地表达了出来，算式b = a+b;其实可以表示为</span> 

<span style="font-size:18px;">b = this.a + b;在这里，this就是个隐式的参数，可以不写。</span>