import java.util.Scanner;
public class nio
{
public static void main(String[] args)
{
StringBuffer sbf = new StringBuffer("ABCDEFG");
System.out.println("sbf的原值"+sbf);
int length = sbf.length();
System.out.println("sbf的长度"+ length);
char chr = sbf.charAt(5);
System.out.println("索引为5的字符为:"+chr);
int index = sbf.indexOf("DEF");
System.out.println("DEF字符串的索引位置为:"+index);
String substr = sbf.substring(0,2);
System.out.println("索引0开始至索引2之间的字符串"+substr);
StringBuffer tmp = sbf.replace(2,5,"1234");
System.out.println("替换后的字符串为:" +tmp);
}
}