循环体我被转晕了。。break换一下位置答案不一样关键我还搞不清

public class Ex1_4_1 {
public static void main(String[] args){
for(int i=1;i<=4;i++)
switch(i) {
case 1: System.out.print("a");
case 2: System.out.print("b");
case 3: System.out.print("c");break;
case 4: System.out.print("d");break;
}
}
}