Java 如何更改实例类变量
我的简化代码如下所示:Java 如何更改实例类变量,java,instance-variables,Java,Instance Variables,我的简化代码如下所示: //class 1 public class Main { public static void main(String[] args) { Process process = new Process(0); //creates new process with ID of 0 process.id = 1; //error - I can't call and change process.id here System.
//class 1
public class Main
{
public static void main(String[] args)
{
Process process = new Process(0); //creates new process with ID of 0
process.id = 1; //error - I can't call and change process.id here
System.out.println(process.id);
}
}
//class 2:
public class Process()
{
//constructor
public Process(int tempID)
{
int id = tempID;
}
}
我有评论错误的地方就是我一直在坚持的地方。我想访问并更改我拥有的这个实例类的id变量,但我不确定如何将id定义为实例变量。
由于id是在方法内部本地定义的,因此可以使用p.id
访问它。
所以创建id作为一个实例变量,比如,为了更新它的值,创建一个setter方法。所以你的班级看起来是这样的
public class Process(){
public int id; //<- Instance Varaible
//constructor
public Process(int tempID){
int id = tempID;
}
//Setter method
public void setId(int id){
int id = tempID;**strong text**
}
}
Process p = new Process(0);
p.setId(1); // Change Value
System.out.println(p.id);