Java字符串操作详解

   public static void main(String[] args){/*
            int i, j;
            for(i=1; i<=9; i++){
                for(j=1; j<=9; j++){
                    if(j


        de5();
        }

        public static void de(){
             int intArray[] = {3,3,3,232};
             for (int i = 0; i < intArray.length; i++) {
                System.out.print(intArray[i]+"  ");
            }

        }
        //只要那个charAt
        public static void de1(){
            String str = "123456789";
            System.out.println(str.charAt(0) + "    " + str.charAt(5) + "    " + str.charAt(8));

        }
        //包含那个contains
        public static void de2(){
            String str = "weixueyuan.pdf";
            System.out.println(str.contains("pdf"));

        }
        //替换那个replace
        public static void de3(){
            String str1 = "The url of weixueyuan is www.weixueyuan.net!";
            String str2 = str1.replace("weixueyuan", "微学苑");
            System.out.println(str1);
            System.out.println(str2);

        }
        //切割那个split
        public static void de4(){
             String str = "wei_xue_yuan_is_good.pdf";
             String strArr[] = str.split(".pdf");
             System.out.println(strArr);
             System.out.println(Arrays.toString(strArr));

        }
      //String buffer
        public static void de5(){
             StringBuffer string = new StringBuffer("wo");
             // string.append("append");//追加
             // string.delete(1, 2);//删除
             //string.indexOf("p");
             //string.insert(2,"insert");//从2开始加
             int capacity = string.capacity();//capacity字符串缓冲区长度,无论多少,都+16
             string.codePointAt(1);
             System.out.println(string);
             System.out.println(capacity);


        }

    }