Java StringBuffer class
Java StringBuffer class is used to create mutable (modifiable) string. The StringBuffer class in java is same as String class except it is mutable i.e. it can be changed.
Note: Java StringBuffer class is thread-safe i.e. multiple threads cannot access it simultaneously. So it is safe and will result in an order.
Important Constructors of StringBuffer class
Important methods of StringBuffer class
What is mutable string
A string that can be modified or changed is known as mutable string. StringBuffer and StringBuilder classes are used for creating mutable string.
1) StringBuffer append() method
The append() method concatenates the given argument with this string.
2) StringBuffer insert() method
The insert() method inserts the given string with this string at the given position.
3) StringBuffer replace() method
The replace() method replaces the given string from the specified beginIndex and endIndex.
4) StringBuffer delete() method
The delete() method of StringBuffer class deletes the string from the specified beginIndex to endIndex.
5) StringBuffer reverse() method
The reverse() method of StringBuilder class reverses the current string.
6) StringBuffer capacity() method
The capacity() method of StringBuffer class returns the current capacity of the buffer. The default capacity of the buffer is 16. If the number of character increases from its current capacity, it increases the capacity by (oldcapacity*2)+2. For example if your current capacity is 16, it will be (16*2)+2=34.
7) StringBuffer ensureCapacity() method
The ensureCapacity() method of StringBuffer class ensures that the given capacity is the minimum to the current capacity. If it is greater than the current capacity, it increases the capacity by (oldcapacity*2)+2. For example if your current capacity is 16, it will be (16*2)+2=34.