Can I conditionally pass a property into an object?

Question

Is it possible to conditionally pass a property into an object-based function:

myFunction
      .x()
      .y()
      .x();

Here, I'd like to only pass in y() based on a condition, something like:

myFunction
      .x()
      [isTrue && y()]
      .x();

Any help much appreciated, thanks

Answer 1

You could use that syntax if you wanted to choose between different methods dynamically. But there's no "do nothing" method that you can substitute in place of y when the condition is false.

Use an if statement instead.

let temp = myFunction.x();
if (isTrue) {
    temp = temp.y();
}
temp.x()

Answer 2

Here's another solution that is more like what you originally imagined. Barmar's solution will work just fine, but I thought I'd show a different approach more like you imagined:

obj
  .x()
  [doIt ? "y" : "noop"]()
  .x();

In this scheme, doIt is any boolean or boolean expression and .noop() is a "do nothing" method on the object.

And, here's a working example you can run in a snippet:

 const obj = { x() { console.log("executing x() method"); return this; }, y() { console.log("executing y() method"); return this; }, noop() { console.log("executing noop() method"); return this; } } // try both values of the boolean for (let doIt of [true, false]) { console.log(`\nresults for doIt = ${doIt}`); obj.x() [doIt? "y": "noop"]().x(); }