思路:
- 使用字符串 repeat() 方法重复 i 次字符 '*'
- 修改某个元素的 HTML 内容使用 .innerHTML
<!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 let character = "*"; let ans = ""; for (let i = 1; i <= 3; i++) { ans = ans + character.repeat(i) + "<br>"; } triangle.innerHTML = ans; </script> </body> </html>