英文:
how do I change instanced class variables
问题
//class 1
public class Main
{
public static void main(String[] args)
{
Process process = new Process(0); //创建一个具有ID 0的新进程
process.id = 1; //错误 - 我不能在这里调用并更改process.id
System.out.println(process.id);
}
}
//class 2:
public class Process()
{
//构造函数
public Process(int tempID)
{
int id = tempID;
}
}
英文:
my code simplified looks something like:
//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;
}
}
Where I have the comment error is what I'm stuck with. I want to access and change the id variable of this instanced class I have, but I'm not sure how to
答案1
得分: 1
# 将 id 定义为实例变量。
由于 id 是在方法内部局部定义的，所以您可以使用 `p.id` 来访问它。
因此，将 id 定义为实例变量，并为更新其值创建一个 setter 方法。因此，您的类将如下所示。
public class Process() {
public int id; //<- 实例变量
// 构造函数
public Process(int tempID) {
id = tempID;
}
// Setter 方法
public void setId(int tempID) {
id = tempID;
}
}
现在您可以像这样更改值
Process p = new Process(0);
p.setId(1); // 更改值
System.out.println(p.id);
英文:
Defined id as an instance variable.
Since id is defined inside the method locally that is why you can access it using p.id.
So create id as an instance variable like and for updating its value create a setter method. So your class would look like this.
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**
}
}
Now you can change the value like this
Process p = new Process(0);
p.setId(1); // Change Value
System.out.println(p.id);
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