Both Object.assign and Object spread only do a shallow merge.  An example of the problem:  // No object nesting const x = { a: 1 } const y = { b: 1 } const z = { ...x, ...y } // { a: 1, b: 1 }   The output is what you'd expect. However if I try...

I was trying to understand what is the difference between spread syntax vs slice method in the following approach.  suppose I want to make an actual copy of an array, I can probably easily do it using spread syntax  var fruits = ["Banana", &#...

New to React.js, I am having hard time using the spread operator in my reducers to update my state that has an 2D-array property.  For instance initial state is so:  let initialState = {     grid: new Array(5).fill(new Array(5).fill(0)),     player:...

I was reading from here about the object spread syntax and I'm trying to use it in my project, my setup is the following:   angular 2 angular/cli 1.0.0-rc.0 ngrx/core 1.2.0 ngrx/store 2.2.1 rxjs 5.1.0 typescript 2.0.10   In my reducer.ts I have...

How can I spread an objects/dict(?) properties and into a new object/dict?  Simple Javascript:  const obj = {x: '2', y: '1'} const thing = {...obj, x: '1'} // thing = {x: '1', y: 1}   Python:  regions = [] for doc in l...

I am trying to create a deep copy map method for my Redux project that will work with objects rather than arrays. I read that in Redux each state should not change anything in the previous states.  export const mapCopy = (object, callback) => {...

I'm trying to convert a data structure like this:  data = {    0:{A:a},    1:{B:b},    2:{C:c},  }   into a structure like this:  [  {0:{A:a}},  {1:{B:b}},   {2:{C:c}}, ]   Using the spread operator like this: [...data] returns any empty array....

I find myself presented with this pattern quite a bit. I have an array of objects that I get back from my api, and I need to manipulate just one of the properties in all of the objects.  Is there a way using ES6/Babel or Typescript to get that patter...

I know one has to be very careful with the function Arguments object  But are there any known downsides (optimization/performance issues) to using the spread syntax with the Arguments object? Or is this totally okay?  I want to create an array from a...

I have added a script that uses ES6 spread operator to the project that gets the params from the url. Unsure how to revert this to the normal vanilla Javascript syntax after I discovered that the project doesn't support ES6.  It's easy to tak...