Adding a Key Value pair to every object within an Array using TypeScript

Question

Adding a Key Value pair to every object within an Array using TypeScript

I have two arrays - one contains dates and the other contains objects. My goal is to include the dates as a key value pair in each object, like this: {"Date": "10-12-18"}.

dates:

["10-12-18", "10-13-18", 10-14-18"]

data:

[
   {"name":"One", "age": "4"},
   {"name":"Two", "age": "5"},
   {"name":"Three", "age": "9"}
]

I envision my final data structure to look something like this...

[
    {"name":"One", "age": "4", "Date": "10-12-18"},
    ....

I am struggling with TypeScript so far as I am more accustomed to regular JavaScript. Here's what I've attempted:

for (let idx of data){
   data[idx].date = dates[idx] 
}

Any tips on how to solve this would be greatly appreciated!

javascript arrays typescript object

Answer 1

Answer №1

Your code has an issue where `idx` refers to the object instead of the index due to the use of `for...of` loop. You should switch to a basic `for` loop like this:

for(let idx = 0; idx < data.length; idx++) {
    data[idx].date = dates[idx];
}

Alternatively, you can utilize `forEach` method to iterate through one array and access values from another array using the provided index:

data.forEach((obj, i) => obj.date = dates[i]);

Answer 2

Your code has an issue where `idx` refers to the object instead of the index due to the use of `for...of` loop. You should switch to a basic `for` loop like this:

for(let idx = 0; idx < data.length; idx++) {
    data[idx].date = dates[idx];
}

Alternatively, you can utilize `forEach` method to iterate through one array and access values from another array using the provided index:

data.forEach((obj, i) => obj.date = dates[i]);

Answer 3

Answer №2

const updatedData = data.map(({ name, age }, index) => ({ name, age, date: dates[index] }));

Transform the array into a new format with the desired result.

Answer 4

const updatedData = data.map(({ name, age }, index) => ({ name, age, date: dates[index] }));

Transform the array into a new format with the desired result.

Answer 5

Answer №3

Here is a similar example:


    let colors = ["blue", "green", "red"];

    let items = [{"type":"car",
     "brand": "Toyota"},

     {"type":"bike",
     "brand": "Honda"},

    {"type":"truck",
     "brand": "Ford"}
    ]

    const updatedItems = items.map((object, idx) => {
        object.Color = colors[idx];
        return object;
    });

console.log(updatedItems);

Answer 6

Here is a similar example:


    let colors = ["blue", "green", "red"];

    let items = [{"type":"car",
     "brand": "Toyota"},

     {"type":"bike",
     "brand": "Honda"},

    {"type":"truck",
     "brand": "Ford"}
    ]

    const updatedItems = items.map((object, idx) => {
        object.Color = colors[idx];
        return object;
    });

console.log(updatedItems);

Answer 7

Answer №4

As mentioned by @Sarah Smith, I strongly believe that utilizing the map operator is the most effective approach.

An alternative method is to employ the spread operator instead of object destructuring, demonstrated below:

const items = [
   { 'name':'Apple', 'quantity': '10' },
   { 'name':'Banana', 'quantity': '5' },
   { 'name':'Orange', 'quantity': '8' }
];

const prices = ['$2', '$3', '$1'];

const output = items.map((item, i) => ({ ...item, price: prices[i] }));

This technique proves particularly useful when dealing with complex objects as it eliminates the need to manually rewrite each key.

Answer 8

As mentioned by @Sarah Smith, I strongly believe that utilizing the map operator is the most effective approach.

An alternative method is to employ the spread operator instead of object destructuring, demonstrated below:

const items = [
   { 'name':'Apple', 'quantity': '10' },
   { 'name':'Banana', 'quantity': '5' },
   { 'name':'Orange', 'quantity': '8' }
];

const prices = ['$2', '$3', '$1'];

const output = items.map((item, i) => ({ ...item, price: prices[i] }));

This technique proves particularly useful when dealing with complex objects as it eliminates the need to manually rewrite each key.

Answer 9

Answer №5

Here is how you can achieve this in TypeScript:

const info = [{
    "name": "John",
    "age": "25"
  },

  {
    "name": "Sarah",
    "age": "32"
  },

  {
    "name": "Mike",
    "age": "45"
  }
];

const dates = ["10-12-21", "10-13-21", "10-14-21"];

console.log(info.map((item, index) => ({ ...item,
  "Date": dates[index]
})));

Answer 10

Here is how you can achieve this in TypeScript:

const info = [{
    "name": "John",
    "age": "25"
  },

  {
    "name": "Sarah",
    "age": "32"
  },

  {
    "name": "Mike",
    "age": "45"
  }
];

const dates = ["10-12-21", "10-13-21", "10-14-21"];

console.log(info.map((item, index) => ({ ...item,
  "Date": dates[index]
})));

Adding a Key Value pair to every object within an Array using TypeScript

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

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