Display list of text using 1 textview

Question

I am trying to display list of results in the same Text View.

Below is my code... this code works but only displays the last value of the for loop.I need the code to print the following.

The result is : 2 * 0 = 0
The result is : 2 * 1 = 2
The result is : 2 * 2 = 4
The result is : 2 * 3 = 6
The result is : 2 * 4 = 8
The result is : 2 * 5 = 10
The result is : 2 * 6 = 12
The result is : 2 * 7 = 14
The result is : 2 * 8 = 16
The result is : 2 * 9 = 18

Kindly advice. Thanks in advance.

@Override
public void onClick(View v) {

    if (v.getId() == R.id.submit){

        for (int i = 0; i < 10; i++) {


            int userInput, result;
            userInput = Integer.parseInt(user.getText().toString());

            result = userInput * i;


            ans.setText("The result is : " + userInput + " * " + i + " = " + result);

            System.out.println("The result is : " + userInput + " * " + i + " = " + result);


        }

    }
}

Answer 1

You can use a String variable to display all the results by using concatfunction and after the loop is executed just set this string to your textView like:

String answerString = "";

@Override
public void onClick(View v) {

    if (v.getId() == R.id.submit){

        for (int i = 0; i < 10; i++) 
        {
            int userInput, result;
            userInput = Integer.parseInt(user.getText().toString());

            result = userInput * i;

            answerString = answerString.concat("The result is : " + userInput + " * " + i + " = " + result);
            answerString = answerString.concat("\n");
        }

        ans.setText(answerString);

    }
}

You can also use "The result is" only one time before the loop and display the result like:

 String answerString = "";

@Override
public void onClick(View v) {

    if (v.getId() == R.id.submit){
        answerString = "The result is : \n";
        for (int i = 0; i < 10; i++) 
        {
            int userInput, result;
            userInput = Integer.parseInt(user.getText().toString());

            result = userInput * i;

            answerString = answerString.concat(userInput + " * " + i + " = " + result);
            answerString = answerString.concat("\n");
        }

        ans.setText(answerString);

    }
}

and your output will be like:

The result is : 
2 * 0 = 0
2 * 1 = 2
2 * 2 = 4
2 * 3 = 6
2 * 4 = 8
2 * 5 = 10
2 * 6 = 12
2 * 7 = 14
2 * 8 = 16
2 * 9 = 18

Answer 2

package com.example.count;

import java.util.Scanner;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {
Button b1;
TextView tv;
int input=2;
int result;
String finalresult="";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        b1=(Button)findViewById(R.id.button1);
        tv=(TextView)findViewById(R.id.txt);
        b1.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
            String res= rint();
                tv.setText(res);
            }
        });
    }

    public String rint(){


         for (int i = 0; i < 10; i++) {
             result = input * i;
             finalresult=finalresult+"\n"+"The result is : " +input + " * " + i + " = " + result;

    }
         return finalresult;
    }
}




<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:text="Button" />

    <TextView
        android:id="@+id/txt"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignRight="@+id/button1"
        android:layout_below="@+id/button1"
        android:layout_marginTop="14dp"
        android:inputType="textMultiLine"
        android:text="@string/hello_world" />

</RelativeLayout>

Answer 3

You can use append instead of setText

example:

ans.append("The result is : " + userInput + " * " + i + " = " + result + "\n");

Or

You can take String variable use += to concatenate the string value and at last after the loop setText to the TextView

example:

String strMultiplication = ""; // declare string before for loop

for (int i = 0; i < 10; i++) {
int userInput, result;
userInput = Integer.parseInt(user.getText().toString());
result = userInput * i;

strMultiplication += "The result is : " + userInput + " * " + i + " = " + result +"\n"); //String concatenation
System.out.println("The result is : " + userInput + " * " + i + " = " + result);
}

ans.setText(strMultiplication); // setText To the textView outside the loop

Answer 4

replace

ans.setText("The result is : " + userInput + " * " + i + " = " + result);

with

ans.append("The result is : " + userInput + " * " + i + " = " + result + "\n");

and your problem is solved

Answer 5

In textview , It will so only the last set the text in textview.

set the text , while i=0 and then next append the text in textview after the for loop increment.

after that you will get the desire result.

    if(i==0)
       ans.setText("The result is : " + userInput + " * " + i + " = " + result);
    else
       ans.append("\nThe result is : " + userInput + " * " + i + " = " + result);