getter和setter并增加一个变量

Cod*_*der 1 java getter setter

public int getA() {
    return a;
}

public void setA(int a) {
    this.a = a;
}
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现在如果我必须增加变量......哪一个是这样做的?

variables.setA(variables.getA()+1);
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这样一来就是1.

我可以解决这个问题吗?

NPE*_*NPE 6

该代码是正确的(如果详细).下列:

public class Main {

    private int a = 0;

    public int getA() {
        return a;
    }

    public void setA(int a) {
        this.a = a;
    }

    public static void main(String[] args)
    {
        Main variables = new Main();
        System.out.println(variables.getA());
        variables.setA(variables.getA()+1);
        System.out.println(variables.getA());
        variables.setA(variables.getA()+1);
        System.out.println(variables.getA());
        variables.setA(variables.getA()+1);
        System.out.println(variables.getA());
    }
}
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鉴于其详细程度variables.setA(variables.getA()+1),您可能希望将其包装到方法中(例如incrementA()addToA(int)等)