Here some important StringBuilder Method in java are given bellow:
| Methods | Description |
| public int capacity() | it is used to return the current capacity. |
| public StringBuilder append(String s) | it is used to append the specified string with this string. The append() method is overloaded like append(char), append(boolean), append(int), append(float), append(double) etc. |
| public StringBuilder delete(int startIndex, int endIndex): | it is used to delete the string from specified startIndex and endIndex. |
| public StringBuilder reverse() |
it is used to reverse the string. |
| public StringBuilder insert(int
offset, String s) |
it is used to insert the specified string with this string at the specified position. The insert() method is overloaded like insert(int, char), insert(int, boolean), insert(int, int), insert(int, float), insert(int, double) etc. |
| public StringBuilder replace(int
startIndex, int endIndex, String str): |
it is used to replace the string from specified startIndex and endIndex. |
public int length() |
it is used to return the length
of the string i.e. total number of characters. |
| public String substring(int beginIndex) | it is used to return the substring from the specified beginIndex |
| public String substring(int beginIndex, int endIndex) | it is used to return the substring from the specified beginIndex and endIndex. |
| public char charAt(int index) | it is used to return the character at the specified position. |
| public void ensureCapacity(int minimumCapacity) | it is used to ensure the capacity
at least equal to the given minimum. |