package answer;

public class answer {

public static void main(String[] args) {

int a = 10,b = 0,i = 4;

b +=a*i;

System.out.println("b的值是："+b);

}

}

public class Demo {

public static void main(String[] args){

     int a=10,b=0;

     for(int i=0;i<3;i++){

          b+=a;

     }

    System.out.println("b="+b);

}

}

public class HelloWorld {

    public static void main(String[] args) {

int a=10,b=0;

b+=a;

b+=a;

b+=a;

b+=a;

System.out.println("b的值:"+b);

    }

}

说简单点其实就是循环4次。