What is the difference between String and StringBuffer in Java?

java string stringbuilder stringbuffer
Praveen picture Praveen · Mar 13, 2010 · Viewed 181.4k times · Source

What is the difference between String and StringBuffer in Java?

Is there a maximum size for String?

Answer

Vivin Paliath picture Vivin Paliath · Mar 13, 2010

String is used to manipulate character strings that cannot be changed (read-only and immutable).

StringBuffer is used to represent characters that can be modified.

Performance wise, StringBuffer is faster when performing concatenations. This is because when you concatenate a String, you are creating a new object (internally) every time since String is immutable.

You can also use StringBuilder which is similar to StringBuffer except it is not synchronized. The maximum size for either of these is Integer.MAX_VALUE (231 - 1 = 2,147,483,647) or maximum heap size divided by 2 (see How many characters can a Java String have?). More information here.

Related questions

How to Reassign value of StringBuffer?

How can we re assign the value of a StringBuffer or StringBuilder Variable? StringBuffer sb=new StringBuffer("teststr"); Now i have to change the value of sb to "testString" without emptying the contents. I am looking at a method which …

Read More
What does " StringBuilders are not thread-safe" mean?

I have read some articles about the pros and cons of String and StringBuilder in the Java Programming language. In one of the articles, the author mentioned that: StringBuilder is not Thread-safe, so in multiple threads use StringBuffer. Unfortunately, I …

Read More
StringBuilder vs String concatenation in toString() in Java

Given the 2 toString() implementations below, which one is preferred: public String toString(){ return "{a:"+ a + ", b:" + b + ", c: " + c +"}"; } or public String toString(){ StringBuilder sb = new StringBuilder(100); return sb.append("{a:").append(a) .append(", b:").append(b) .append(", c:").append(…

Read More