What is StringBuffer class?
StringBuffer is a string class that provides much of the functionality of mutable strings. StringBuffer makes strings growable and writable. StringBuffer can either have characters or substrings inserted in the middle or appended to the end. It grows to make room for additions and has more characters preallocated than are needed to allow room for growth. To create a string buffer, an object needs to be created.
StringBuffer str = new StringBuffer();
Implementation in a code
The following is an example which implements the StringBuffer class.
Code:
public class Ninja {
public static void main(String args[])
{
StringBuffer str = new StringBuffer("Coding");
str.append(" Ninjas!");
System.out.println(str);
}
}
Output:
Coding Ninjas!
Also see, Swap Function in Java
What is Stringbuilder Class?
This class is similar to StringBuffer in Java, representing a mutable sequence of characters. The StringBuilder class provides an alternative to String Class, i.e., creating a mutable sequence of characters. The function of StringBuilder is also much similar to the StringBuffer class. To create a new string with the name str, we need to create an object of StringBuilder.
StringBuilder str = new StringBuilder();
Implementation in a code
The following is an example which implements the StringBuilder class.
Code:
public class Ninja {
public static void main(String args[])
{
StringBuilder str = new StringBuilder("Coding");
str.append(" Ninjas!");
System.out.println(str);
}
}
Output:
Coding Ninjas!
You can also read about the topic of Java Destructor and Hashcode Method in Java.
Conversion from StringBuffer to StringBuilder
StringBuffer can be converted to StringBuilder function as shown in the following example:
Code:
public class Ninja {
public static void main(String args[])
{
StringBuffer sbr = new StringBuffer("Ninjas");
String str = sbr.toString();
StringBuilder sbl = new StringBuilder(str);
System.out.println(sbl);
}
}
Output:
Ninjas
Explanation:
In the above code, we first converted the StringBuffer to a String object using the built-in method toString() because we cannot directly convert the StringBuffer to StringBuilder. After converting it to a string object, we created a StringBuilder using the class's constructor.
Conversion from StringBuilder to StringBuffer
StringBuilder can be converted to StringBuffer function as shown in the following example:
Code:
public class Ninja {
public static void main(String args[])
{
StringBuilder sbl = new StringBuilder("Ninjas");
String str = sbl.toString();
StringBuffer sbr = new StringBuffer(str);
System.out.println(sbr);
}
}
Output:
Ninjas
Explanation:
In the above code, the StringBuilder cannot be converted to the StringBuffer directly. So, we first converted the StringBuilder to the String object using the built-in method toString(). Then we created a StringBuffer using the constructor. Try this code by yourself on Online Java Compiler.
When to Use StringBuffer vs StringBuilder
Choosing between StringBuffer and StringBuilder depends on your application's threading needs and performance requirements.
Choosing Based on Threading Requirements
Use StringBuffer when thread safety in Java string manipulation is important. It is synchronized, meaning only one thread can access it at a time, making it safe for concurrent operations.
Use StringBuilder in single-threaded applications. It is not synchronized, so it performs better in environments where thread safety is not a concern.
StringBuffer vs StringBuilder performance:
StringBuilder is faster than StringBuffer because it avoids the overhead of synchronization.
Real-World Scenarios and Examples
When to use StringBuffer in Java:
Logging events from multiple threads to a shared buffer.
StringBuffer log = new StringBuffer();
// Threads appending logs concurrently
log.append("User logged in\n");
When to use StringBuilder:
Building a report string in a desktop app loop.
Understanding the context of use helps you select the right class for efficient and safe string handling.
StringBuilder report = new StringBuilder();
for (int i = 0; i < 100; i++) {
report.append("Line ").append(i).append("\n");
}
Advantages and Disadvantages
When working with mutable strings in Java, understanding the performance vs thread safety in Java strings is essential. Below is a simple breakdown of the StringBuffer advantages and disadvantages and the StringBuilder pros and cons to help you choose the right one for your application.
StringBuffer: Advantages and Disadvantages
Advantages:
- Thread-safe: All methods are synchronized, making it safe for use in multi-threaded environments.
- Reliable in concurrency: Prevents data corruption when multiple threads access or modify the same string.
Disadvantages:
- Performance overhead: Synchronization adds extra processing, making it slower in single-threaded applications.
- Unnecessary complexity: Not needed if thread safety isn't a concern, leading to inefficient code.
StringBuilder: Pros and Cons
Advantages:
- High performance: Faster than StringBuffer due to the absence of synchronization.
- Ideal for single-threaded use: Great for desktop applications, loops, and data formatting.
Disadvantages:
- Not thread-safe: Unsafe in concurrent scenarios, which can lead to data inconsistency.
- Limited use in multi-threaded programs: Requires external synchronization if used across threads.
Frequently Asked Questions
Which is faster StringBuilder or buffer?
StringBuilder is generally faster than StringBuffer because it is not synchronized, making it more efficient in single-threaded environments where synchronization is unnecessary.
Why StringBuffer is slower than StringBuilder?
StringBuilder is faster than StringBuffer because it's not synchronized.
Why do we use buffer and builder classes in java?
String is immutable whereas StringBuffer and StringBuilder are mutable classes. So they are used to make strings mutable.
Why is String builder more efficient?
StringBuilder is a lot faster than StringBuffer, therefore, more efficient.
Conclusion
In this article, we have extensively discussed StringBuffer and StringBuilder classes and their differences with different code examples. Having gone through this article, I am sure you must be excited to read similar blogs. Coding Ninjas has got you covered. Here are some similar blogs to redirect:
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