Question

I know this is a little dumb, but how do you do this? I’ve “RTFM” but I still don’t understand concepts like this just don’t exist in the languages I’m used to programming. Anyway, my question is simple: how does one properly set a global variable which can be used by all public void functions inside that class?

Here is some example code, I will highlight the redundancy in case you don’t see it:

public class baketimer extends Activity implements OnClickListener {
    /** Called when the activity is first created. */

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        final Button cupcake1 = (Button) this.findViewById(R.id.cupcake1);

        cupcake1.setOnClickListener(this);        
    }

    public void onClick(View v) {
        switch(v.getId()){
        case R.id.cupcake1:
            final Button cupcake1 = (Button) this.findViewById(R.id.cupcake1);
            new CountDownTimer(30000, 1000) {

                public void onTick(long millisUntilFinished) {
                    cupcake1.setText("" + millisUntilFinished / 1000);
                }

                public void onFinish() {
                    cupcake1.setText("Done!");
                }
            }.start();
            Toast.makeText(this, "Mmm cupcakes!", Toast.LENGTH_SHORT).show();
            break;

How would I go about declaring cupcake1 for the entire class?

Thanks in advance!

Answer 1

Declare the variable inside the class and outside any function, but not necessarily static.

public class YourClass{
    Button cupcake = null;
    public void onCreate(Bundle savedInstanceState) {
        ...
        cupcake = (Button) this.findViewById(R.id.cupcake1);
        ...
    }
    public void onClick(Bundle savedInstanceState) {
        ...
    }
}

Use static (static Button cupcake = ...) if you want the variable to be shared by ALL objects – aka ALL instances of the class – in your program. Otherwise, don’t use static, so that the variable only belongs to that object.