StringBuffer类的添加功能

===============append 练习一====================

package ss1;

/**
 * StringBuffer类的添加功能：
 *
 * public StringBuffer append(boolean b) //追加任意类型数据，返回的是他本身
 * public StringBuffer insert(int offset, boolean b) //插入数据
*/
public class Menu {
 public static void main(String[] args) {
  StringBuffer sb = new StringBuffer();
  StringBuffer sb2 =sb.append("hello");
  System.out.println(sb);
  System.out.println(sb2);
  System.out.println(sb2 == sb );
 }
}

结果:

hello
hello
true

========================append 练习二========================

public class Menu {
 public static void main(String[] args) {
  StringBuffer sb = new StringBuffer();
  sb.append("hello");
  sb.append(true);
  sb.append(12);
  System.out.println(sb);
 }
}

结果:

hellotrue12

=========================append 练习三=====================

public class Menu {
 public static void main(String[] args) {
  StringBuffer sb = new StringBuffer();
  sb.append("hello") .append(true).append(12);
  System.out.println(sb);
 }
}

结果:

hellotrue12

=====================insert  练习四=====================

public class Menu {
 public static void main(String[] args) {
  StringBuffer sb = new StringBuffer();
  sb.append("hello").append(true).append(12);
  System.out.println(sb);
  sb.insert(5, "word");
  System.out.println(sb);
 }
}

结果:

hellotrue12
hellowordtrue12