说明
实现下图效果:
<script type="text/javascript">
for( var a = 1 ; a <= 9 ; a++){
var line = ""
// b的最大值是 a
for( var b = 1 ; b <= a; b++){
line = line +"\t" + a+"*"+b+"="+(a*b)
}
console.log(line)
}
</script>
