2. public StringBuilder insert(int offset, String s): 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. 3. public StringBuilder replace(int startIndex, int endIndex, String str): is used to replace the string from specified startIndex and endIndex.
2. public String substring(int startIndex,int endIndex): នេះជាវិធី method returns String object ថ្មីដែលផ្ទុក substring ដែលបានផ្តល់ string មានលក្ខណ:ជា startIndex ទៅ endIndex.