Java StringBuffer vs StringBuilder

Java StringBuffer vs StringBuilder

StringBuffer

The StringBuffer class is used to create mutable string. StringBuffer shows writable and growable character sequences.

Java StringBuffer program

FileName: StringBufferExample.java

 // A basic program that demonstrates the working of StringBuffer
public class StringBufferExample
{ 
// main method
public static void main(String[] argvs)
{ 
    // creating an object of the class StringBuffer
    StringBuffer sb = new StringBuffer("Hi "); 
    // appending the string Tutorial & Example
    sb.append("Tutorial & Example "); 
    // displaying the output
    System.out.println(sb); 
} 
}  

Output:

Hi Tutorial & Example

StringBuilder

The StringBuilder class is also used to create mutable string. The StringBuilder is same as the StringBuffer class. The difference is StringBuilder class is not synchronized whereas the StringBuffer class is synchronized

Java StringBuilder Program

FileName: StringBuilderExample.java

 // A basic program that demonstrates the working of StringBuilder
public class StringBuilderExample
{ 
// main method
public static void main(String[] argvs)
{ 
    // creating an object of the class StringBuffer
    StringBuilder sb = new StringBuilder("Hi "); 
    // appending the string Tutorial & Example
    sb.append("Tutorial & Example "); 
    // displaying the output
    System.out.println(sb); 
} 
}  

Output:

Hi Tutorial & Example

Difference Between StringBuffer and StringBuilder

The following table describes the key differences between StringBuffer and StringBuilder in Java.

StringBuffer	StringBuilder
StringBuffer is a mutable, thread-safe, and synchronized. Thread-safe means two or more than two threads are not allowed to access the same method of the StringBuffer class simultaneously.	StringBuilder class is also a mutable but it is not thread-safe and not synchronized. Thread-safe means two or more than two threads are allowed to access the same method of the StringBuilder class simultaneously.
StringBuffer is not that much efficient as compared to StringBuilder.	StringBuilder performs better, i.e., more efficient as compared to StringBuffer.

Performance Comparison Between StringBuffer and StringBuilder class

We know that StringBuilder is quick as compared to StringBuffer. Let’s check it with the help of a Java program.

FileName: PerformanceTestExample.java

 // A basic Java program that compares the performance of StringBuffer and 
// StringBuilder
public class PerformanceTestExample
{ 
// main method
public static void main(String argvs[])
{ 
long sTime = System.currentTimeMillis();
// creating an object of StringBuffer
StringBuffer strBuffer = new StringBuffer("Hi "); 
for (int j = 0; j < 10000; j++)
{ 
     // doing the concatenation work
    strBuffer.append("Tutorial & Example"); 
}
// displaying the time taken by StringBuffer
System.out.println("Total Time consumed by the StringBuffer is: " + (System.currentTimeMillis() - sTime) + "ms"); 
// resetting the start time
sTime = System.currentTimeMillis();
// creating an object of StringBuilder
StringBuilder strBuilder = new StringBuilder("Hi "); 
for (int j = 0; j < 10000; j++)
{ 
     // doing the concatenation work
    strBuilder.append("Tutorial & Example"); 
} 
// displaying the time taken by StringBuilder
System.out.println("Total Time consumed by the StringBuilder is: " + (System.currentTimeMillis() - sTime) + "ms");
} 
}  

Output:

 Total Time consumed by the StringBuffer is: 4ms
Total Time consumed by the StringBuilder is: 3ms 

Explanation: Observe the output, we see that StringBuilder is quicker as compared to StringBuffer.