We may decide to execute a function not right now, but at a later time. That’s called “scheduling a call”.

There are two methods for it:

• setTimeout allows us to run a function once after the interval of time.
• setInterval allows us to run a function repeatedly, starting after the interval of time, then repeating continuously at that interval.

These methods are not a part of JavaScript specification. But most environments have an internal scheduler and provide these methods. In particular, they are supported in all browsers and Node.js.

setTimeout

The syntax:

let timerId = setTimeout(func|code, [delay], [arg1], [arg2], ...)

Parameters:

func|code: Function or a string of code to execute.

Usually, that’s a function. For historical reasons, a string of code can be passed, but that’s not recommended.

delay: The delay before running, in milliseconds (1000 ms = 1 second), by default 0.

arg1, arg2: Arguments for the function (not supported in IE9-)

#javascript #programming #scheduling