Function returns undefined unless specified otherwise

Why is my function returning undefined when I have not mentioned that anywhere.

The crux of the issue is in the topic header.

All functions have to return something. If nothing is specified, they return undefined.

function doSomething() {
  // do something
}

const something = doSomething();
console.log("something: ", something);
// undefined

You may however chose to ignore receiving something from the function.

function doSomething() {
  // do something
}

doSomething();

Typically, I like to return at least a true or false - just for the heck of it. That’s overengineering to some, but that’s ok.

function doSomething() {
  // do something
  return true;
}