How to Convert int to double in Java?

In Java, an int value can be converted into a double value by using the simple assignment operator. This is because this conversion is an example of Type Promotion(Implicit type conversion) in which a lower data type is automatically converted into a higher data type.

Here, the int values are converted into double values implicitly by using the assignment operator.

public class StudyTonight
{  
    public static void main(String args[])
    {  
        int i = 500;  
        double l = i;  
        System.out.println(" The double value is : " +l); 
    }
}

Output:

The double value is : 500.0

Also, we can convert an int value into a Double Object either by instantiating Double class or by using the Double.valueOf() method.

Here, the int value is converted into the double by instantiating the class and using valueOf() method.

public class StudyTonight
{  
    public static void main(String args[])
    {  
        int i = 200;  
        double d1 = new Double(i);  //conversion using the instantiation  
        double d2 = Double.valueOf(i); //conversion using the valueOf() method  
        System.out.println(d1);  
        System.out.println(d2);  
    }
}

Output:

200.0 200.0