如何在对象数组中设置每个对象的属性？

Question

I have this array as example:

array = [{id:3},{id:2},{id:4}]

I want to loop through this array of objects, and make each "id" from each object equal to its index position inside of the array, to make something like this:

array =[{id:0},{id:1},{id:2}]

Any idea of how can I do this?

Thank you all for the attention!

Answer 1

Simple map would work:

 const array = [{id:3},{id:2},{id:4}]; const newArray = array.map((e, i) => ({ id: i })); console.log(newArray); 

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If you want to keep all other properties the same (if you have multiple properties):

 const array = [{id:3, name: "A"},{id:2, name: "B"},{id:4, name: "C"}]; const newArray = array.map((e, i) => ({ ...e, id: i })); console.log(newArray); 

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Answer 2

Using forEach metohd will loop to every object in the array then to change a property value of an object to the index of the element you must pass the object and its index as the second args then equate it to the object property.

let array = [{id:3},{id:2},{id:4}] 
 array.forEach((item, index) => { 
 item.id = index 
})

Answer 3

For completeness, you can loop over an array with a simple for loop:

for (var i = 0; i < array.length; i++) {
  array[i].id = i;
}