console 命令行工具 X clear

console

document.write("<table>");
var str = "js九九乘法表";
document.write("<h1>" + str + "</h1>");
for ( var x = 1; x <= 9; x++) {
    document.write("<tr>");
    for ( var y = 1; y <= x; y++) {
        document.write("<th>" + x + "*" + y + "=" + (x * y) + "</th>");
    }
    document.write("</tr>");
}
document.write("</table>");

/**
 * es6语法
 */
class Point {
  constructor(x, y) {
    this.x = x;
    this.y = y;
  }
  /*正序*/
  zx() {
    for (let i = this.x; i <= this.y; i++) {
      let str = "";
      for (let j = this.x; j <= i; j++) {
        str += "|" + i + "*" + j + "=" + (i * j)+"\t";
      }
      str += "|";
      console.log(str);
    }
  }
  /*倒叙*/
  dx(){
    for (let i=this.y;i>=this.x;i--) {
      let str="";
      for (let j=this.x;j<=i;j++){
        str += "|" + i + "*" + j + "=" + (i * j)+"\t";
      }
      str+="|";
      console.log(str);
    }
  }
}

var ss = new Point(1, 9);
ss.zx();
ss.dx();

<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>九九乘法表</title>
</head>
<body>

</body>
<script src="js/app.js"></script>
</html>