import java.util.*; public class string_builder { public static void main(String[] args) { StringBuilder sb = new StringBuilder("Hello"); System.out.println(sb); sb.append(" World"); // append(charSequence S) System.out.println("append(): " + sb); sb.append("a!bc", 1, 2); // append(charSequence s, int start, int end): appends the specified substring of a string System.out.println("append(s, num1, num2): " + sb); System.out.println("capacity(): " + sb.capacity()); // capacity(): returns current capacity of the sb System.out.println("charAt(i): " + sb.charAt(3)); // charAt(int index) sb.deleteCharAt(4); // deleteCharAt(int index) System.out.println("deleteCharAt(4): " + sb); sb.delete(6, 8); // delete(int start, int end) System.out.println("delete(6, 8): " + sb); System.out.println("equals(sb): " + sb.equals(new StringBuilder("Hello"))); // equals(sb) System.out.println("indexOf(s): " + sb.indexOf("W")); // indexOf(String s) sb.insert(6, "or"); // insert(int position, String s) sb.insert(4, "o"); System.out.println(sb); System.out.println("length(): " + sb.length()); // length() sb.replace(0, 5, "Hi"); // replace(int start, int end, String s) System.out.println("replace(0, 5, hi): " + sb); System.out.println("reverse(): " + sb); // reverse() System.out.println("substring(2,6): " + sb.substring(2, 6)); // substring(int start, int end) String s = sb.toString(); //toString() System.out.println("toString(): " + s); } }