CODEWITHSUNDEEP
javaandroid
user3640056
user3640056

Reputation: 732

Android Calculate percentage

I'm new to android and Java, and I have to design a simple application that reads an amount and shows a 10 percent of this amount in a toast. This is my code:

activity_main.xml:

 <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/amount"
        android:hint="Bill amount in L.L"
        android:layout_marginTop="53dp"
        android:layout_below="@+id/text"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:inputType="number"/>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="10%"
        android:id="@+id/button"
        android:layout_below="@+id/amount"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="65dp"
        android:onClick="tenp"/>

MainActivity.java:

 public void tenp(View view1) {

       EditText e = (EditText) findViewById(R.id.amount);


        double amount = Double.parseDouble(e.getText().toString());

        double res = (amount / 100.0f) * 10;

        Toast.makeText(getApplicationContext(), "" +res, Toast.LENGTH_SHORT).show();

    }

When I run my app and click on the 10% button, the app closes. I don't know what is my error here. please help.

Upvotes: 3

Views: 32759

Answers (1)

Sanjeet A
Sanjeet A

Reputation: 5227

Your code is fine except for the handling the invalid parsing of double. You can modify your code for the invalid parsing of double as-

public void tenp(View view1) {

        EditText e = (EditText) findViewById(R.id.amount);
        if (!e.getText().toString().equals("")) {
            double amount = Double.parseDouble(e.getText().toString());
            double res = (amount / 100.0f) * 10;
            Toast.makeText(getApplicationContext(), "" + res, Toast.LENGTH_SHORT).show();
        }else{
            Toast.makeText(getApplicationContext(), "Amount cannot be empty", Toast.LENGTH_SHORT).show();

        }

    }

Upvotes: 20

Related Questions