🎓 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
Introduction
Converting a string into a list of characters is a common task in Java programming. This can be useful in various scenarios, such as string manipulation, character frequency analysis, or simply breaking down a string into its constituent characters. This blog post will explore different methods for converting a string into a list of characters in Java.
Table of Contents
- Using a Loop
- Using
String.toCharArray() - Using Streams (Java 8+)
- Complete Example Program
- Conclusion
1. Using a Loop
A straightforward way to convert a string into a list of characters is by using a loop to iterate over each character in the string and add it to a list.
Example:
import java.util.ArrayList;
import java.util.List;
public class StringToListUsingLoop {
public static void main(String[] args) {
String str = "Hello World";
// Convert string to list of characters using a loop
List<Character> charList = new ArrayList<>();
for (char c : str.toCharArray()) {
charList.add(c);
}
System.out.println("String: " + str);
System.out.println("List of Characters: " + charList);
}
}
Output:
String: Hello World
List of Characters: [H, e, l, l, o, , W, o, r, l, d]
Explanation:
- A loop is used to iterate over each character in the string and add it to the
charList.
2. Using String.toCharArray()
The String.toCharArray() method converts a string into a character array. This array can then be used to create a list of characters.
Example:
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class StringToListUsingToCharArray {
public static void main(String[] args) {
String str = "Hello World";
// Convert string to list of characters using toCharArray()
char[] charArray = str.toCharArray();
List<Character> charList = new ArrayList<>();
for (char c : charArray) {
charList.add(c);
}
System.out.println("String: " + str);
System.out.println("List of Characters: " + charList);
}
}
Output:
String: Hello World
List of Characters: [H, e, l, l, o, , W, o, r, l, d]
Explanation:
- The
toCharArray()method converts the string into a character array, which is then added to thecharList.
3. Using Streams (Java 8+)
Java 8 introduced the Stream API, which provides a more concise way to convert a string into a list of characters.
Example:
import java.util.List;
import java.util.stream.Collectors;
public class StringToListUsingStreams {
public static void main(String[] args) {
String str = "Hello World";
// Convert string to list of characters using streams
List<Character> charList = str.chars()
.mapToObj(c -> (char) c)
.collect(Collectors.toList());
System.out.println("String: " + str);
System.out.println("List of Characters: " + charList);
}
}
Output:
String: Hello World
List of Characters: [H, e, l, l, o, , W, o, r, l, d]
Explanation:
- The
chars()method returns anIntStreamof characters from the string. - The
mapToObj(c -> (char) c)method converts eachintcharacter to aCharacterobject. - The
collect(Collectors.toList())method collects the characters into a list.
4. Complete Example Program
Here is a complete program that demonstrates all the methods discussed above to convert a string into a list of characters in Java.
Example Code:
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
public class StringToListExample {
public static void main(String[] args) {
String str = "Hello World";
// Using Loop
List<Character> charList1 = new ArrayList<>();
for (char c : str.toCharArray()) {
charList1.add(c);
}
System.out.println("Using Loop: " + charList1);
// Using toCharArray() Method
char[] charArray = str.toCharArray();
List<Character> charList2 = new ArrayList<>();
for (char c : charArray) {
charList2.add(c);
}
System.out.println("Using toCharArray(): " + charList2);
// Using Streams
List<Character> charList3 = str.chars()
.mapToObj(c -> (char) c)
.collect(Collectors.toList());
System.out.println("Using Streams: " + charList3);
}
}
Output:
Using Loop: [H, e, l, l, o, , W, o, r, l, d]
Using toCharArray(): [H, e, l, l, o, , W, o, r, l, d]
Using Streams: [H, e, l, l, o, , W, o, r, l, d]
5. Conclusion
Converting a string into a list of characters in Java can be accomplished in several ways. Using a loop and String.toCharArray() are straightforward and easy to understand. The Stream API, introduced in Java 8, provides a more concise and functional approach. By understanding these different methods, you can choose the one that best fits your needs and coding style.
Happy coding!
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
![[NEW] Learn Apache Maven with IntelliJ IDEA and Java 25](https://img-c.udemycdn.com/course/750x422/6852721_b512_2.jpg "[NEW] Learn Apache Maven with IntelliJ IDEA and Java 25")
[NEW] Learn Apache Maven with IntelliJ IDEA and Java 25
ChatGPT + Generative AI + Prompt Engineering for Beginners
Spring 7 and Spring Boot 4 for Beginners (Includes 8 Projects)
Available in Udemy for Business
Building Real-Time REST APIs with Spring Boot - Blog App
Available in Udemy for Business
Building Microservices with Spring Boot and Spring Cloud
Available in Udemy for Business
Java Full-Stack Developer Course with Spring Boot and React JS
Available in Udemy for Business
Build 5 Spring Boot Projects with Java: Line-by-Line Coding
Testing Spring Boot Application with JUnit and Mockito
Available in Udemy for Business
Spring Boot Thymeleaf Real-Time Web Application - Blog App
Available in Udemy for Business
Master Spring Data JPA with Hibernate
Available in Udemy for Business
Spring Boot + Apache Kafka Course - The Practical Guide
Available in Udemy for Business
Comments
Post a Comment
Leave Comment