Understanding String and String Pool in Java

Photo by B K on Unsplash

Java is renowned for its powerful memory management and optimization techniques. One of the core components that facilitate this efficiency is the String class and the concept of the String pool. While these concepts might seem straightforward, understanding their nuances can significantly impact your application's performance and memory usage. In this post, we'll delve into the details of String and the String pool in Java, exploring how they work and how to leverage them for optimal results.

The String Class

String is a fundamental class in Java, representing a sequence of characters. Here are some key characteristics of the String class:

Immutable

In Java, String objects are immutable. This means that once a String object is created, its value cannot be changed. Any operation that seems to modify a string, such as concatenation, actually creates a new String object with the new value. For example:

String str1 = "Hello";
String str2 = str1.concat(" World");
System.out.println(str1); // Outputs: Hello
System.out.println(str2); // Outputs: Hello World

In the above code, str1 remains unchanged after the concatenation operation. Instead, str2 is a new String object with the value "Hello World".