Map array of objects

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Please read carefully the question, this is not a duplicate of:

  • ECMAScript 6 arrow function that returns an object
  • javascript cannot map array of objects with nested values
  • map function for objects (instead of arrays)
  • Loop through an array in JavaScript
  • map function for objects (instead of arrays)
  • Loop through an array in JavaScript

Let's consider the following array of object:

var obj = [{ 'key1' : 'value1' }, { 'key2' : 'value2' }];

I would like to map the array to get keys and values for each object. Something like:

obj.map((key, val) => console.log(key, val));

I already try many stuff like Object.entries(obj) but it always results in complicated solution with many brackets like Object.entries(obj)[0][1]

Is there a simple, nice and efficient way to map an array of object? Note I need key and value for each object

You seem like you only want to print it out or access them:

.map changes an array to a different array, which doesn't seem like what you are looking for.

var objs = [{ 'key1' : 'value1' }, { 'key2' : 'value2' }];

objs.forEach(obj => { 
  for (let p in obj) console.log(p, obj[p]); 
});

How To Use .map() to Iterate Through Array Items in JavaScript , You just need to wrap object in (). var arr = [{ id: 1, name: 'bill' }, { id: 2, name: 'ted' }] var result = arr.map(person => ({ value: person.id, text:� The map method is cloning the array as it is intended to do, but since we have an array of objects, each item is actually only a reference to the object in memory. This means, it is essentially

var obj = [{ 'key1' : 'value1' }, { 'key2' : 'value2' }];
obj.forEach(el => {
  for (var prop in el) {
    console.log(prop, el[prop])
  }
})

// results: 
// key1 value1
// key2 value2

ES6 map an array of objects, to return an array of objects with new , map(). Let me explain how it works with a simple example. Say you have received an array containing multiple objects – each one representing a� I have an array of objects. I would like to map this array of objects. I know how to map an array, but can't figure out how to map an array of objects. Here is what I have done so far : The arr

Not as clean as what @nopole answer, but this kind achieve what you want for a key, value object.

var objs = [{ 'key1' : 'value1' }, { 'key2' : 'value2' }];

objs.forEach(obj => { 
  // loop over keys-and-values
  for (let [key, value] of Object.entries(obj)) {
    console.log(key, value);
  }
});

Simplify your JavaScript – Use .map(), .reduce(), and .filter(), Extracting object keys with map. For example, if we wanted to use map to extract a single key from every item in an array of objects, we could do it� Definition and Usage The map () method creates a new array with the results of calling a function for every array element. The map () method calls the provided function once for each element in an array, in order. Note: map () does not execute the function for array elements without values.

Deep Dive into JavaScript's Array Map Method, The map() method creates a new array with the results of calling a function for every array element. The map() The array object the current element belongs to� You essentially trick the program into thinking the object is an array by using Object.keys which will allow you to use the map function with its acting on the values the individual keys are associated with (I actually accidentally returned arrays but fixed it).

JavaScript Array map() Method, This tutorial shows you how to use the JavaScript Array map method to transform elements in an array based on The array is the array object being traversed. Just like .map(), .reduce() also runs a callback for each element of an array. What’s different here is that reduce passes the result of this callback (the accumulator) from one array element to

JavaScript Array map() Method: Transforming Array Elements, Objects for storing keyed collections. Arrays for storing ordered collections. But that's not enough� Transform objects of an array - Array.map. This is something we need very often. Transform an array of objects into an array of different objects. That's a job for Array.map. Let's say we want to classify our cars into three groups based on their size.

Comments
  • objs.flatMap(Object.entries) should do?
  • What is the expected output value, to what do you want to map the array of objects? Your "something like" only does log the keys and values, which is trivial and does not need map. What exactly do you need?
  • I want to create a HTTP request like key1=value1&key2=value2, but I already know how to do that, I just have difficulties accessing the object keys and values.
  • Please show your code then. It seems you have no problem with iterating through the array, but just getting key and value from the object? The solution to that would be to use a less weird input format - why an array of single-property objects instead of one object with multiple properties that you could simply enumerate?
  • @Fifi what final result are you looking for? Is your expected result an array, or a single obj, and what values are in it?
  • Thank you, but the question is about the map() method. I know how to loop over an array.
  • @Fifi please see second part of answer
  • Yes, that it. Not as simple as I expected, but I guess this is the shortest syntax. Thank you.
  • I want to use the map method.
  • use .map insted of .foreach, it works also on this way
  • @Fifi But why? You still haven't told us yet what kind of array value you want to produce, and if you don't produce another array you should not use map.