java《StringBuffer类》

//StringBuffer类
package test1;
import java.util.*;
public class Main {
    
    
    public static void main(String[] args) {
    
    
        System.out.println("1.添加---------------");
        StringBuffer sb = new StringBuffer();
        sb.append("SBC");
        System.out.println("append添加结果："+sb);
        sb.insert(3,"DE");//在指定位置插入字符串
        System.out.println("insert添加结果"+sb);
        System.out.println("2.修改---------------");
        StringBuffer sb1 = new StringBuffer("ABAAA");
        sb1.setCharAt(2,'c');
        System.out.println("修改指定位置字符结果："+sb1);
        sb1.replace(3,5,"DE");
        System.out.println("替换指定位置字符串结果："+sb1);
        System.out.println("字符串翻转结果："+sb1.reverse());

        System.out.println("3.删除---------------");
        StringBuffer sb2 = new StringBuffer("ABCDEFG");
        sb2.delete(3,7);
        System.out.println("删除指定位置结果："+sb2);
    }
}

Output result:
1. Add ---------------
append Add result: SBC
insert add result SBCDE
2. Modify ---------------
modify the designation Position character result: ABcAA
replace the specified position string result: ABcDE
string flip result: EDCBA
3. Delete ---------------
Delete the specified position result: ABC

Process finished with exit code 0