for循环嵌套实现打印九九乘法口诀表/倒三角(JavaScript)

倒三角形

<script>
var str = '';
for (var x = 1; x <= 9; x++) {
for (var y = 1; y <= x; y++) {
str += '⭐';
}
str += '\n';
}
console.log(str);
</script>

九九乘法口诀表

<script>
var sum, str = '';  //str空字符串用于存放打印的数据  sum表示x与y的乘积
for (var x = 1; x <= 9; x++) {
for (var y = 1; y <= x; y++) {
sum = x * y;
str += y + '  *  ' + x + '  =  ' + sum + '\t';
}
str += '\n';
}
console.log(str);

</script>