Confusion with Recursion

JavaScript
1

I tried different ways, it doesn’t seem to work. Can someone tell me what I’m doing wrong? Thank you.

  **My code so far**


function rangeOfNumbers(startNum, endNum) {
  if (endNum == startNum) {
    return [startNum];
  } else {
    /*startNum = startNum <= endNum;*/
    const myArray = rangeOfNumbers(endNum - startNum);
    myArray.push(endNum);
    myArray.unshift(startNum);
    return myArray;
  }
}
2

How many parameters does rangeOfNumbers take?

1 Like
3

Two parameters. Can you also explain why I had to use square braces in the third line around startNum ?

4

I’m not trying to answer your question, just noticed something that i didn’t get.
How do you push a number onto another number if the last is not an array or in one? so far i learned that you can push an element to an array not to number or a string. Unless when you do that javascript creates an array for them.just guessing.
Thank you.

5

So why are you calling it with only one?

The square brackets mean you are creating an array, the output of the function should always be an array

6

But he did it only in the if statement not the else statement, so how is the else statement output gonna be ? Will it get outputed in an array automatically?
I see in that code that he is trying to push a value to the function call, does that mean that the function call’s returned value is in an array already?

7

Yes, the function returns an array

1 Like
8

Hi @zak,
Is always a good idea to remember that an algorithm or solution is different from its implementation.

… Will it get outputed in an array automatically?

… does that mean that the function call’s returned value is in an array already?

… i learned that you can push an element to an array not to number or a string. Unless when you do that javascript creates an array for them.just guessing.

JS(the implementation) uses some abstractions: call stack and nested calls that you need to know to answer your questions.

I tried to explain this in another thread:

Cheers and happy coding :slight_smile:

1 Like
9

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