javascript - 我无法正确输出

Question

for (var j = 1; j <= 10; j++) {
    for (var i = 10; i >= j; i--) {
        document.write(i * 10 + ' ')
    }
    document.write('<BR>');
}

我一直在尝试得到这个输出:

100 90 80 70 50 40 30 20 10 
-----------------
90 90 70 60 50 40 30 20 10 
-----------------
80 70 60 50 40 30 20 10 
-----------------
70 60 50 40 30 20 10 
-----------------
60 50 40 30 20 10 
-----------------
50 40 30 20 10 
-----------------
40 30 20 10 
-----------------
30 20 10
-----------------
20 10
-----------------
10
-----------------

但我得到的只是这个:

100 90 80 70 60 50 40 30 20 10 
-----------------
100 90 80 70 60 50 40 30 20 
-----------------
100 90 80 70 60 50 40 30  
-----------------
100 90 80 70 60 50 40 
-----------------
100 90 80 70 60 50 
-----------------
100 90 80 70 60 
-----------------
100 90 80 70 
-----------------
100 90 80
-----------------
100 90
-----------------
100
-----------------

请帮忙。

Answer 1

 for (var j = 10; j >= 1; --j) {
     for (var i = j * 10; i >= 10; i -= 10) {
         document.write(i + ' ')
     }
     document.write('<BR>');
 }

Reverse loop is best fit in your case to improve understandability & performance.