How to convert Double type to primitive data type using doubleValue() method of Double class

How to use the doubleValue() method of the Double class to convert the Double type to a primitive data type

In Java, the Double class is a wrapper class that represents a double-precision floating point number. Sometimes, we need to convert Double type values ​​into primitive data types, such as int, float, long, etc. At this time, we can use the doubleValue() method provided by the Double class to achieve this.

The doubleValue() method is an instance method of the Double class, used to return the original data type value of the current Double object. The specific usage is as follows:

public class DoubleConversionExample {
    public static void main(String[] args) {
        Double doubleValue = 3.14; // 声明一个Double对象

        // 使用doubleValue()方法将Double类型转换为原始数据类型
        double primitiveValue = doubleValue.doubleValue();

        System.out.println("Double Value: " + doubleValue);
        System.out.println("Primitive Value: " + primitiveValue);
    }
}

In the above example code, we first declare a Double object doubleValue and assign it a value of 3.14. Then, we convert it to the primitive data type double using the doubleValue() method and assign the converted value to the primitiveValue variable. Finally, we output the Double type value and the primitive data type value through print statements respectively.

Run the above code, the output result is as follows:

Double Value: 3.14
Primitive Value: 3.14

As you can see, the doubleValue() method does successfully convert the Double type value into the original data type double.

In addition to converting to double type, the same method also applies to other primitive data types. For example, if we need to convert the Double type to the int type, we can use the intValue() method:

Double doubleValue = 3.14;
int primitiveValue = doubleValue.intValue();

Similarly, if we need to convert the Double type to the float type, we can use the floatValue() method:

Double doubleValue = 3.14;
float primitiveValue = doubleValue.floatValue();

It should be noted that due to the precision limitations of floating point numbers, conversion to primitive data types may result in loss of precision. Therefore, when performing type conversion, it is recommended to use a wrapper class corresponding to the original data type to store values.

In addition, if you want to convert a Double type object into a wrapper class of other data types, you can use the corresponding valueOf() method. For example, convert the Double type to the Integer type:

Double doubleValue = 3.14;
Integer integerValue = Integer.valueOf(doubleValue.intValue());

To summarize, the doubleValue() method of the Double class is one of the common methods to convert the Double type to the original data type. In actual development, we often need to perform this type conversion operation to meet the needs between different data types. By flexibly using the methods provided by the Double class, we can easily perform type conversion.

The above is the detailed content of How to convert Double type to primitive data type using doubleValue() method of Double class. For more information, please follow other related articles on the PHP Chinese website!