<script>
var h = prompt("(正三角)请输入欲打印的行数","");
for(var i=1;i<=h;i++){
if(i%2==0){
var color="red";
}else{
var color="blue";
}
document.write("<hr size='5' color='"+color+"' width='"+i+"%'>");
}
</script>
使用for循环输出hr标签打印正三角形
洒脱<script> var h ...