Java Double parseDouble() example

🎓 Top 15 Udemy Courses (80-90% Discount): My Udemy Courses - Ramesh Fadatare — All my Udemy courses are real-time and project oriented courses.

▶️ Subscribe to My YouTube Channel (178K+ subscribers): Java Guides on YouTube

▶️ For AI, ChatGPT, Web, Tech, and Generative AI, subscribe to another channel: Ramesh Fadatare on YouTube

In this guide, you will learn about the Double parseDouble() method in Java programming and how to use it with an example.

1. Double parseDouble() Method Overview

Definition:

The parseDouble() method of the Java Double class converts a string representation of a floating-point number to its double primitive type.

Syntax:

double Double.parseDouble(String s)

Parameters:

String s: The string to be parsed.

Key Points:

- If the string does not contain a parsable double, a NumberFormatException will be thrown.

- This method can handle string representations of both regular floating-point numbers and numbers in scientific notation.

- Leading and trailing whitespaces in the string are allowed and will be ignored during the parsing.

- The method is static, so it's invoked on the class (Double) and not on an instance of the class.

2. Double parseDouble() Method Example

public class ParseDoubleExample {
    public static void main(String[] args) {
        // Parse a regular floating-point number
        String numberStr = "123.45";
        double value = Double.parseDouble(numberStr);
        System.out.println("Parsed double from string: " + value);

        // Parse a number in scientific notation
        String sciNotationStr = "1.23e2"; // Represents 1.23 * 10^2
        double sciValue = Double.parseDouble(sciNotationStr);
        System.out.println("Parsed double from scientific notation: " + sciValue);
    }
}

Output:

Parsed double from string: 123.45
Parsed double from scientific notation: 123.0

Explanation:

In the provided example, we first parsed a regular floating-point number "123.45" from a string using the parseDouble() method. 

We then demonstrated the method's capability to handle scientific notation by parsing the string "1.23e2", which represents the value \(1.23 \times 10^2\), resulting in a double value of 123.0.

My Top and Bestseller Udemy Courses. The sale is going on with a 70 - 80% discount. The discount coupon has been added to each course below:

Build REST APIs with Spring Boot 4, Spring Security 7, and JWT

🆕 High-Demand 80–90% OFF

[NEW] Learn Apache Maven with IntelliJ IDEA and Java 25

🆕 High-Demand 80–90% OFF

ChatGPT + Generative AI + Prompt Engineering for Beginners

🚀 Trending Now 80–90% OFF

Spring 7 and Spring Boot 4 for Beginners (Includes 8 Projects)

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Building Real-Time REST APIs with Spring Boot - Blog App

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Building Microservices with Spring Boot and Spring Cloud

🌟 Top Rated 80–90% OFF
Available in Udemy for Business

Java Full-Stack Developer Course with Spring Boot and React JS

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Build 5 Spring Boot Projects with Java: Line-by-Line Coding

🌟 Top Rated 80–90% OFF

Testing Spring Boot Application with JUnit and Mockito

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Spring Boot Thymeleaf Real-Time Web Application - Blog App

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Master Spring Data JPA with Hibernate

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Spring Boot + Apache Kafka Course - The Practical Guide

🎓 Student Favorite 80–90% OFF
Available in Udemy for Business

Java Testing: Mastering JUnit 5 Framework

🆕 New 80–90% OFF

Reactive Programming in Java: Spring WebFlux and Testing

🌟 Top Rated 80–90% OFF

Spring Boot + RabbitMQ Course - The Practical Guide

🌟 Top Rated 80–90% OFF
Available in Udemy for Business

Functional Programming in Java (Includes Java Collections)

🎓 Student Favorite 80–90% OFF

ChatGPT for Java Developers: Boost Your Productivity with AI

🚀 Trending Now 80–90% OFF