Double parseDouble() method in Java with examples

The parseDouble() method of Java Double class is a built in method in Java that returns a new double initialized to the value represented by the specified String, as done by the valueOf method of class Double.

Syntax:

public static double parseDouble(String s)

Parameters: It accepts a single mandatory parameter s which specifies the string to be parsed.

Return type: It returns e double value represented by the string argument.

Exception: The function throws two exceptions which are described below:

• NullPointerException– when the string parsed is null
• NumberFormatException– when the string parsed does not contain a parsable float

Below is the implementation of the above method.

Program 1:

// Java Code to implement
// parseDouble() method of Double class

class GFG {

    // Driver method
    public static void main(String[] args)
    {

        String str = "100";

        // returns the double value
        // represented by the string argument
        double val = Double.parseDouble(str);

        // prints the double value
        System.out.println("Value = " + val);
    }
}

Output:

Value = 100.0

Program 2: To show NumberFormatException

// Java Code to implement
// parseDouble() method of Double class

class GFG {

    // Driver method
    public static void main(String[] args)
    {

        try {

            String str = "";

            // returns the double value
            // represented by the string argument
            double val = Double.parseDouble(str);

            // prints the double value
            System.out.println("Value = " + val);
        }
        catch (Exception e) {
            System.out.println("Exception: " + e);
        }
    }
}

Output:

Exception: java.lang.NumberFormatException: empty String

Program 3: To show NullPointerException

// Java Code to implement
// parseDouble() method of Double class

class GFG {

    // Driver method
    public static void main(String[] args)
    {

        try {

            String str = null;

            // returns the double value
            // represented by the string argument
            double val = Double.parseDouble(str);

            // prints the double value
            System.out.println("Value = " + val);
        }
        catch (Exception e) {
            System.out.println("Exception: " + e);
        }
    }
}

Output:

Exception: java.lang.NullPointerException

Reference: https://docs.oracle.com/javase/7/docs/api/java/lang/Double.html#parseDouble(java.lang.String)