[Java] [Conceptos básicos] StringBuffer

package itheima2;
public class Main {
    
    
    public static void main(String[] args) {
    
    
        StringBuffer stringBuffer = new StringBuffer("This is a StringBUffer!");
        //查找匹配字符串
        System.out.println(stringBuffer.indexOf("is"));
        System.out.println(stringBuffer.indexOf("is",4));
        System.out.println(stringBuffer.lastIndexOf("is"));
        System.out.println(stringBuffer.lastIndexOf("is",1));
        
        //截取字符串
        System.out.println(stringBuffer.substring(2));
        System.out.println(stringBuffer.substring(2,9));
        
        //获取字符串某个位置的字符
        System.out.println(stringBuffer.charAt(2));
        
        //添加各种类型的数据到尾部
        stringBuffer.append('I');
        System.out.println(stringBuffer);
        stringBuffer.append(new char[]{
    
    ' ','a','m'});
        System.out.println(stringBuffer);
        stringBuffer.append(" in 、BeiJing.");
        System.out.println(stringBuffer);
        stringBuffer.append(15);
        System.out.println(stringBuffer);
        stringBuffer.append(899L);
        System.out.println(stringBuffer);
        
        //删除字符中的数据
        stringBuffer.delete(1,5);;
        System.out.println(stringBuffer);
        
        //在指定位置插入各种类型数据
        stringBuffer.insert(8,"abc");
        System.out.println(stringBuffer);
        
        //替换某些字符串 
        stringBuffer.replace(3,8,"replace");
        System.out.println(stringBuffer);
        
        //将字符串倒序
        System.out.println(stringBuffer.reverse());

        
    }
}

La diferencia entre String, StringBuffer y StringBuilder en java (una breve introducción)

Estas funciones son muy similares a las cadenas de Python y más poderosas que la clase Java String.