How to define a constant that could be either bolean, function and timeout function?

Question

let delay = false
...
delay && clearTimeout(delay)
        delay = setTimeout(() => {
            callfunc(string, signal)
        }, 2000)

I got delay var and I want it to be either bolean, function and timeout function. What type should it be?

Answer 1

// set time out always returns a unique id, which will always be a number.

 let timeoutId: Number; // renamed
    timeoutId && clearTimeout(timeoutId)
            timeoutId= setTimeout(() => {
                callfunc(string, signal)
            }, 2000)

Read more here: what does settimeout return