Does setTimeout in JavaScript accept real (floating point) delay times_

问题

I was just looking at JavaScript Timing Events, and there it says that "The second parameter indicates how many milliseconds from now you want to execute the first parameter."

Now, I know that in JavaScript, both floating point and integers are of type Number, and so syntactically I can enter a floating point value, e.g. 'setTimeout("javascript statement",4.5);' - however, will JavaScript even attempt to create a delay of 4.5 milliseconds there; or will it just automatically truncate to integer and go on?

Thanks in advance for any answers,
Cheers!

回答1:

This is almost certainly browser-dependent (I haven't checked it's not part of the language spec), but typically this value is stored in a 32-bit signed int, so would only accept integer values between 0 and 2^31 - 1.

Related:

• Why does setTimeout() "break" for large millisecond delay values?
• 7.3 Timers — HTML Standard

来源：https://stackoverflow.com/questions/7286178/does-settimeout-in-javascript-accept-real-floating-point-delay-times