在Javascript中嵌套调用函数

Question

Intellij IDEA shows a warning when ever I write Javascript like this:

someFunction(someOtherFunction());

But the explanation is not really helpful:

"This inspection reports any Javascript function calls used as arguments to another function call."

This is something I do frequently, so what's the potential trap hiding there worth warning of? Or if it's just some coding convention, what's the reason for it?

Answer 1

It is a warning because most of the time, you want to pass a function reference as an argument. It is mostly used as a callback:

someFunction(someOtherFunction);
function someFunction(fn){
    fn.call();
}

In that example, someOtherFunction() instead of someOtherFunction would not work as expect (unless someOtherFunction returns a function itself).

someFunction(someOtherFunction()); work more like a getter.

someFunction(someOtherFunction());
function someFunction(int){
    alert(int === 1);//True;
}
function someOtherFunction(){
    return 1;
}

It gives a warning because it is a common mistake for new developers.