stringbuffer2.java

java程序设计 清华出版社 孙燮华老师编写的程序源代码

//StringBuffer2.java
//appeng(), insert(), setcharAt()应用举例
public class StringBuffer2{
  public static void main(String[] args) {
    Object h = "Hello";
    String s = "good bye";
    char cc[ ] = {'a', 'b', 'c', 'd', 'e', 'f'};
    boolean b = false;
    char c = 'Z';
    long k = 12345678;
    int  i = 88;
    float f = 2.5f;
    double d = 3.1415926;
    
    StringBuffer bufApp=new StringBuffer();
    bufApp.append(h);    bufApp.append(f);    bufApp.append(cc); 
    bufApp.append(i);    bufApp.append(b);    bufApp.append(k); 
    bufApp.append(s);    bufApp.append(d);    bufApp.append(c);
    System.out.println("bufApp = " + bufApp);
  
    StringBuffer bufIns=new StringBuffer();
    bufIns.insert(0, h); bufIns.insert(0, f); bufIns.insert(0, cc);
    bufIns.insert(0, i); bufIns.insert(0, b); bufIns.insert(0, k); 
    bufIns.insert(0, s); bufIns.insert(0, d); bufIns.insert(0, c);
    System.out.println("bufIns = " + bufIns);
    
    StringBuffer bufSet=new StringBuffer(s);
    System.out.println("\nbufSet = "+bufSet.toString()+".  After using setCharAt(0,'G')");
    bufSet.setCharAt(0,'G');   //将bufSet串下标为0的字符改写为'G'
    bufSet.setCharAt(5,'B');   //将下标为5的字符改写为'B'
    System.out.println("and setCharAt(5,'B'), bufSet = "+ bufSet.toString());    
  }
}