字符串连接符 +

package operator;

public class Demo07 {
    public static void main(String[] args) {
        //字符串连接符 +
        int a = 10;
        int b = 20;

        a += b;//a = a + b
        


        System.out.println(a+b);
        System.out.println(""+a+b);//string类型
        System.out.println(a+b+"");//依旧运算
    }
}