请补全JavaScript代码,要求在页面上渲染出一个直角三角形,三角形换行要求使用"br"实现。三角形如下:
*
**
***
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
</head>
<body>
<div class='triangle'></div>
<script>
var triangle = document.querySelector('.triangle');
// 补全代码
str = ''
for(var i=0;i<3;i++) {
for(var j=0;j<=i;j++) {
str += '*';
}
str += '</br>';
}
triangle.innerHTML = str;
</script>
</body>
</html> <!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
</head>
<body>
<div class="triangle"></div>
<script>
var triangle = document.querySelector('.triangle')
// 补全代码,尽量写的有点拓展性吧
let str = '', char = '*', len = 3
for (let i = 0; i < len; i++) {
for (let j = 0; j <= i; j++) {
str += char
}
str += '<br>'
}
triangle.innerHTML = str
</script>
</body>
</html>