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How to ensure a specific property order in JSON objects using JavaScript?

I have a JSON array containing objects, and I want to ensure that the "id" property is always at the beginning of each object. The order of keys in a JSON object doesn’t affect its functionality, but for my use case, I need "id" to be the first in every object. How can I achieve this?

const jsonData = [
  {
    "id": 40,
    "front": "Define the concept of a skew-symmetric matrix.",
    "back": "A skew-symmetric (or antisymmetric) matrix is a square matrix whose transpose is equal to its negative. In other words, A matrix A is skew-symmetric if A^T = -A.",
    "lastModified": "2023-12-21T12:30:45.789Z",
    "status": "Want to Learn"
  },
  {
    "front": "front1",
    "back": "back1",
    "lastModified": "2024-01-01T17:44:39.040Z",
    "status": "Want to Learn",
    "id": 41
  }
];

This is my function to add new cards:

const handleAddCard = async (card) => {
    try {
      const newCard = {
        ...card,
        lastModified: new Date().toISOString(),
      };

      const res = await fetch("http://localhost:3001/flashcards", {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify(newCard),
      });

      if (!res.ok) {
        throw new Error("Failed to add card");
      }

      setFlashCards([...flashcards, card]);

      setNewCard(false);

      setCardAdded(true);
    } catch (error) {
      console.error("Error adding card:", error);
    }
  };
Tags:

3

Answers


  1. 0

    You could write a function that places id first using the spread operator. Something like this.

    function reorderCard(card) {
  const { id, ...rest } = card;
  return { id, ...rest };
}

const handleAddCard = async (card) => {
  try {
    const orderedCard = reorderCard(card);
    // other logic
  } catch (err) {
    //error handling
  }
};
    Login or Signup to reply.
  2. 0 
      Hi you can just add one liner code to achieve this.

  id: card.id

whole function will be shown as below

 const handleAddCard = async (card) => {
   try {
  const newCard = {
  id: card.id,
     ...card,
      lastModified: new Date().toISOString(),
   };

   const res = await fetch("http://localhost:3001/flashcards", {
    method: "POST",
     headers: {
    "Content-Type": "application/json",
     },
     body: JSON.stringify(newCard),
    });

    if (!res.ok) {
     throw new Error("Failed to add card");
    }

    setFlashCards([...flashcards, card]);

    setNewCard(false);

    setCardAdded(true);
    } catch (error) {
    console.error("Error adding card:", error);
    }
   };
    Login or Signup to reply.
  3. 0

    "I need "id" to be the first in every object."

    Somewhere you have this code

    for (let prop in obj) {
  // do something with prop, obj[prop]
  // oh no its out of order!
}

    You could instead use this code

    let fieldOrder = ["id", "status", "front", "back", "lastModified"];

for (let prop of fieldOrder) {
  // do something with prop, obj[prop]
  // in the order specified by the array above
}

    You could compute fieldOrder from an object containing unknown properties (that has id)

    let fieldOrder = ["id", ...Object.keys(obj).filter(k => k !== "id")];
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