java种StringBuilder

package frank;
import java.lang.*;

public class App
{
	public static void main(String[] args) throws Exception
	{
		StringBuilder sb = new StringBuilder();
		System.out.println(sb.capacity());
		for(int i = 0;i<20;i++)
		{
			sb.append(i);
		}
		sb.insert(0,"h");//插入
		sb.replace(5,6,".");//替换
		sb.delete(5,6);//删除
		sb.reverse();//反转
		System.out.println(sb.toString());
		System.out.println(sb.length());//获得长度
		System.out.println(sb.capacity());//得到最大容量]
		sb.setLength(18);//设置长度，超出的省略掉。
		System.out.println(sb.toString());
	}
}