javascript/timing

Question

我想使用Java脚本计算单击 两个按钮之间的时间差

Answer 1

Here's a hint - use:

var t = Date.now();

to get the current time (measured in milliseconds since 00:00:00 UTC on 01/01/1970) with millisecond resolution .

Note that the result will still be limited in accuracy by the system hardware.

On older browsers without Date.now() , use:

var t = new Date().valueOf();

or the terser

var t = +new Date();

The latter uses numeric coercion (the + prefix) to generate an automatic call to .valueOf() .

Answer 2

• Get current time from the epoch in milliseconds: new Date().getTime() .
• Difference between times: endTime - startTime .
• Show message box: alert("Message") .

Guess these can be combined together as needed.

Answer 3

还可以考虑使用performance.now（）获得更高分辨率的时序。