StringBuilder的基础使用

package com.utils.String_builder_buffer;






public class StringBuilderType {
    public static void main(String[] args) {
//        setCapacityLength();
        actualOperation();
    }

    
    public static void  setCapacityLength(){
        //添加初始字符串
        StringBuilder setCL = new StringBuilder("123456789123456789");
        System.out.println("添加的初始字符串：" + setCL);
        System.out.println("字符串长度为：" +setCL.length());
        
        System.out.println("超过初始容量后的容量：" + setCL.capacity());
        
        setCL.append("abcd");
        System.out.println("再加上一个字符串,字符串长度为：" +setCL.length());
        System.out.println("再加上一个字符串,超过初始容量后的容量：" + setCL.capacity());
        //添加初始容量
        StringBuilder setL = new StringBuilder(18);
        System.out.println("设置的新容量:" + setL.capacity());
    }

    
    public static void actualOperation(){
        
        StringBuilder strbb = new StringBuilder();
        strbb.append("abc").append(true).append(123);
        System.out.println(strbb);

        
        strbb.insert(2,"在第二位后新增");
        System.out.println(strbb);

        
        //StringBuffer delete(start,end):删除缓冲区中的数据，包含Start,不包含end
        //StringBuffer deleteCharAt(index)；删除缓冲区指定位置的数据
        strbb.delete(3,4);
        System.out.println("删掉下标3到4的内容,包3不包4: " + strbb);
        strbb.deleteCharAt(0);
        //删除下标为0
        System.out.println("删除下标为0: " + strbb);

        
        System.out.println("输出下标为3：" + strbb.charAt(3));
        System.out.println("输出字符为位的下标：" + strbb.indexOf("位"));

        
        //replace(int start,int end,String str) 也是包start，不包end
        //setCharAt(int index,String str)
        strbb.replace(0,1,"Z");
        System.out.println(strbb);
        strbb.setCharAt(0,'b');
        System.out.println(strbb);

        
        System.out.println(strbb.reverse());


    }


}