clear a value from a string android

Question

I have an app that lets you click buttons to add and subtract +5 or -5 and +1 or -1 from a starting value of 20. I have it set up so that when a button is clicked it will put that value into a string and display it so that the user can see a history of what they have pressed. I have a method called reset(); that resets the starting value back to 20, I would like to know how to also clear the string values

add5.setOnClickListener(new View.OnClickListener() {

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        counter += 5;
        updateDisplay();

        // add the click history for p1
        String tmText = (String) btnPressedTV.getText();
        btnPressedTV.setText(tmText + "\n" + String.valueOf(counter));
    }
});

sub5.setOnClickListener(new View.OnClickListener() {

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        counter -= 5;
        updateDisplay();

        // add the click history for p1
        String tmText = (String) btnPressedTV.getText();
        btnPressedTV.setText(tmText + "\n" + String.valueOf(counter));
    }
});

    void reset() {
    // TODO Auto-generated method stub
    counter = 20;
    display.setText(String.valueOf(20));
    display.setTextColor(Color.BLACK);
    tmText = ""; 

}

Is your value 20 stored in `counter` variable ? Can you show your code of `reset()` method? — GrIsHu, Dec 23 '13 at 04:14
At the time of reset.set the string value as `null`. counter value equal to 0. — Yugesh, Dec 23 '13 at 04:25

score 2 · Accepted Answer · answered Dec 23 '13 at 04:30

2

Try this..

Use your String tmText in Global like below and as like your integer counter

String tmText;
int counter;

and reset method

public void reset()  
{
    tmText = ""; 
    counter = 20; 
}

answered Dec 23 '13 at 04:30

Hariharan

24,741
6
50
54

I added what you have here and it still does not reset the string when the reset function is called. – user3104719 Dec 23 '13 at 15:31
@user3104719 where have you called the `reset()` method – Hariharan Dec 23 '13 at 15:32
I call the reset function through a menu option, it resets the int counter back to the starting value of 20 as well as resets the color of the text to black(it changes to red or green based on the number). Those will reset like they should, the string does not. – user3104719 Dec 23 '13 at 15:40
@user3104719 in that add `btnPressedTV.setText("");` – Hariharan Dec 23 '13 at 15:54
I had a mistype, it works just like you said it would. Thank you! – user3104719 Dec 23 '13 at 21:19

Nidhish Krishnan · Answer 2 · 2013-12-23T04:22:33.147

Make sure that the String should be class variable and not local variable.
To clear a call variable String value try this

class Sample
{
 String str; // class variable (string)
 int counter=20; // class variable (integer)
 :
 :
 :
 reset.setOnClickListener(new View.OnClickListener() {  // button click
    @Override
    public void onClick(View v) {
       str = ""; // you can clear the string value like this
       counter = 20; // you can reset the integer value like this 
    }
 });
 :
 :
 :
 public void resetfunction()  // method
 {
  str = ""; // you can clear the string value like this
  counter = 20; // you can reset the integer value like this
 }
 :
 :
 :
}

score 0 · Answer 3 · answered Dec 23 '13 at 04:28

0

You can reset ur String by assigning double quotes to it by

str = "";

answered Dec 23 '13 at 04:28

Vivek Warde

1,936
8
47
77

score 0 · Answer 4 · edited May 23 '17 at 12:19

I suggest using implementing OnClickListener in your class. The difference explained here The different OnClickListener implementation ways

Here is some code to explain what I mean:

public class MainActivity extends Activity implements OnClickListener {

    Button add5;
    Button sub5;
    Button reset;

    int counter;
    String tmText;

    @Override
    public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main_activity);

    //init the counter var
    counter = 20;


    //get handles to the buttons in your xml declaration
    add5 = (Button) findViewById(R.id.add5);
    sub5 = (Button) findViewById(R.id.sub5);
    reset = (Button) findViewById(R.id.reset);

    //attach the buttons the onclickListener
    add5.setOnClickListener(this);
    sub5.setOnClickListener(this);
    reset.setOnClickListener(this);

    @Override
    public void onClick(View arg0) {
        switch(arg0.getId()) {
        case R.id.add5:
            // +5 code
            break;
        case R.id.sub5:
            // minus 5 code
            break;
        case R.id.reset;
            counter = 20;
            tmText = "";
        }
    }
}

If you are looking to clear the values displayed in a textview:

TextView myTextView = (TextView) findViewById(R.id.myTextView);
myTextView.setText("");

clear a value from a string android

4 Answers4

Linked