如何在 android 工作室中从另一个 class 访问变量

Question

hey guys i wanted to use the variables of lets say class 1 in method A() in the class2 i have tried the following

class1 obj = new class1();
obj.A();

but its throwing an error saying cannot resolve symbol A()

Answer 1

Just declare your variables to be public:

  public int variable1;
  public int variable2;

  Class1() {
      this.variable1 = 400;
      this.variable2 = 600;
  }

Class1 obj = new Class1();
obj.variable1;

Or just make them private and add getters:

  private int variable1;
  private int variable2;

  Class1() {
    this.variable1 = 400;
    this.variable2 = 600;
  }

  public int getVariable1() {
     return this.variable1;
  }

  public int getVariable2() {
     return this.variable2;
  }

then

Class1 obj = new Class1();
obj.getVariable1()

Answer 2

you have to return that variable, like this:

class Class1 {
    public int A() {
        int a = 5 + 6;
        return a;
    }
}

You need to add this return statement: return a; at the end of A() function to return the value