NumberFormatException...Invalid Double

Question

I used three edit texts to create an app that calculates acceleration but when the user inputs a wrong number that's invalid like ".3" or does not input any number , I get an invalid double error "" ".3" respectively .. i am using android studio kotlin codes ... Please add source codes to explanation

<EditText
        android:id="@+id/v1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:autofillHints=""
        android:ems="10"
        android:hint="@string/initial_velocity"
        android:inputType="numberSigned|numberDecimal"
        android:textColor="#F8F5F5"
        android:textColorHint="#FFFFFF"
        android:textSize="24sp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <EditText
        android:id="@+id/s"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="24dp"
        android:autofillHints=""
        android:ems="10"
        android:hint="@string/time"
        android:inputType="numberSigned|numberDecimal"
        android:textColor="#FFFFFF"
        android:textColorHint="#FAF6F6"
        android:textSize="24sp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/v2" />

    <Button
        android:id="@+id/acceleration"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="32dp"
        android:background="#FFFFFF"
        android:text="@string/acceleration1"
        android:textColor="#070707"
        android:textSize="18sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/s" />

    <TextView
        android:id="@+id/n"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#FFFFFF"
        android:textSize="24sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

    <TextView
        android:id="@+id/s1"
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        android:text="@string/ms"
        android:textColor="#EDECEC"
        android:textSize="24sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toEndOf="@+id/n" />

    <TextView
        android:id="@+id/textView5"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="24dp"
        android:text="@string/_2g"
        android:textColor="#FFFFFF"
        android:textSize="18sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toEndOf="@+id/s1" />

    <EditText
        android:id="@+id/v2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="24dp"
        android:autofillHints=""
        android:ems="10"
        android:hint="@string/final_velocity"
        android:inputType="numberSigned|numberDecimal"
        android:textColor="#FFFFFF"
        android:textColorHint="#FFFFFF"
        android:textSize="24sp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/v1" />

val Int:Number=(((v2.text.toString().toDouble())-(v1.text.toString().toDouble()))/(s.text.toString().toDouble()))
            n.setText(Int.toString())
            Toast.makeText(this, "Acceleration equals", Toast.LENGTH_LONG).show()
        }
    }
    fun Math (Int:Number) {
        val Int:Number=(((v2.text.toString().toDouble())-(v1.text.toString().toDouble()))/(s.text.toString().toDouble()))
        n.setText(kotlin.Int.toString())
    }
}

score 0 · Answer 1 · answered Sep 19 '20 at 14:45

It seems your are declaring an integer val Int: and are trying to calculate double values

try this instead

val Double:Number=(((v2.text.toString().toDouble())-(v1.text.toString().toDouble()))/(s.text.toString().toDouble()))
            n.setText(Double.toString())
            Toast.makeText(this, "Acceleration equals", Toast.LENGTH_LONG).show()
        }
    }
    fun Math (Double:Number) {
        val Double:Number=(((v2.text.toString().toDouble())-(v1.text.toString().toDouble()))/(s.text.toString().toDouble()))
        n.setText(kotlin.Double.toString())
    }
}

NumberFormatException...Invalid Double

1 Answers1