方法一:
<script>
var n = 5;
//行数
for (var i = 1; i <= n; i++) {
//打印空格 n-i 总层数-第几层
for (var j = 1; j <= (n - i); j++) {
document.write(" ");
}
//打印*
for (var k = 1; k <= i; k++) {
document.write("*");
}
//换行
document.write("<br>");
}
</script>
方法二:
<script>
var n = 5;
//行数
for (var i = 1; i <= n; i++) {
//打印空格 n-i 总层数-第几层
for (var j = 1; j <= i-1; j++) {
document.write(" ");
}
//打印*
for (var k = 5; k >= i; k--) {
document.write("*" + " ");
}
//换行
document.write("<br>");
}
</script>