Getting undefined instead of the return value of a function

Question

I have this simple array of two objects where I need to get the price of the products of 1 month.

The array can 2 or 3 items so I'm checking whether it is 2 or 3. Then I'm storing the objects in their own variable and calling the function getOneMonthPrice with parameter value of those variables.

The function getOneMOnthPrice loops over the products and checks if the months property as a value of 01 month, and if it does then it returns the price.

But right now I'm only getting undefined, whereas if I use console.log inside the functions, I can see the values showing in the console.

What is going wrong here?

Please note that I have actually removed most of the codes from the actual project where I'm working on. This is just the shortest version. If you can please give me a solutoin based on this format.

Here's the snippet:

const arr = [{
    "name": "Boom Boom Ltd.",
    "products": [{
        "price": "3.33",
        "months": "24 months"
      },
      {
        "price": "10.95",
        "months": "01 month"
      }
    ]
  },
  {
    "name": "Bam Bam Ltd.",
    "products": [{
        "price": "5.93",
        "months": "24 months"
      },
      {
        "price": "12.95",
        "months": "01 month"
      }
    ]
  }
];


function getOneMonthPrice(company) {
  company.products.forEach(item => {
    if (item.months === "01 month") {
      return item.price;
    }
  });
};


if (arr.length === 2) {
  const company1 = arr[0];
  const company2 = arr[1];

  console.log(getOneMonthPrice(company1));
}

score 0 · Accepted Answer · answered Apr 01 '21 at 15:48

0

Returning from the forEach callback function doesn't return from the containing function.

Instead of forEach, you can use find() to find the array element that matches your criteria, then return the price from that.

function getOneMonthPrice(company) {
  let product = company.products.find(item => item.months === "01 month");
  return product && product.price;
}

answered Apr 01 '21 at 15:48

Barmar

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Hey man thanks for your time. Just for learning purposes, can you tell me what could have been done if I really wanted to use forEach? – s.khan Apr 01 '21 at 15:52
See the other answer. – Barmar Apr 01 '21 at 15:53
But why would you really want to use `forEach`? – Barmar Apr 01 '21 at 15:54
Okay. Last question regarding your answer. Why did you return both the product object && its price? Returning only product.price would have been enough right? – s.khan Apr 01 '21 at 15:54
I don't. Just to know if there's actually a way to do this with forEach. – s.khan Apr 01 '21 at 15:55
1

I do that in case no product is found. If I just return `product.price` it will get an error if `product == null` – Barmar Apr 01 '21 at 15:55
1

@A.Amit you can't short circuit, or stop, a forEach, so there's no value in doing it with a foreach for most, if not all, scenarios. – Kevin B Apr 01 '21 at 15:56
1

It's roughly equivalent to `if (product) return product.price;` – Barmar Apr 01 '21 at 15:56
Understood. Thanks a lot for your answer. I'm confused which one to choose now. – s.khan Apr 01 '21 at 15:57
2

You should choose mine because it stops searching as soon as it finds the month. `forEach` will keep processing the rest of the array. – Barmar Apr 01 '21 at 15:59
1

@A.Amit Choose Barmar's. His is the better answer unless you break out of your forEach. – Hanlet Escaño Apr 01 '21 at 16:00
Got it. Thanks a lot. And I have not been downvoting it btw just to let you guys know. – s.khan Apr 01 '21 at 16:01

Getting undefined instead of the return value of a function

1 Answers1