I have an array of objects like this
const initialState = [
{
id: 1, author: 'author 1', title: 'Book 1', category: 'Category 1',
},
{
id: 2, author: 'author 2', title: 'Book 2', category: 'Category 2',
},
{
id: 3, author: 'author 3', title: 'Book 3', category: 'Category 3',
},
];
if one object is removed, for example; the object with id of 2 is removed. I want to reset the id properties of the remaining properties so they follow an order of 1, 2, 3...
I have done this with;
let id = 1
state.forEach(object => {
object.id = id
id += 1
})
Is there a much better way to do this? like using the map function?
Your code can be improved just by using the index
state.forEach((object, index) => {
object.id = index + 1
})
You can also use map function as you suggested but it will return a new array
const newArray = state.map((object, index) => {
object.id = index + 1
})
If you want to follow immutable practices (if that's what you mean by better), you can use the spread operator (or Object.assign):
const initialState = [
{
id: 1, author: 'author 1', title: 'Book 1', category: 'Category 1',
},
// commented out for demonstration: this element would be "removed".
//{
//id: 2, author: 'author 2', title: 'Book 2', category: 'Category 2',
//},c
{
id: 3, author: 'author 3', title: 'Book 3', category: 'Category 3',
},
];
const newState = initialState.map((obj, i) => ({ ...obj, id: i + 1 }));
console.log(initialState)
console.log(newState)