prompt+date.now打字计时器

挺有趣的一个交互，记录一下

var start = Date.now();var response = prompt("What is your name?", "");var end = Date.now();var elapsed = (end - start) / 1000;document.write("You took " + elapsed + " seconds" + " to type: " + response);// Output:// You took <seconds> seconds to type: <name>