用数组内部的对象破坏分配

Question

Is there a way to unpack values from an array of objects using destructuring assigments?

[

{a : 1},
{a : 1},
{a : 1},
{a : 1}

]

The result I need here is an array: [1,1,1,1]

Answer 1

Destructuring that would require the creation of 4 separate variables which would then get recombined into an array later. It would be very WET, and wouldn't make much sense, but if you had to:

 const arr = [ {a : 1}, {a : 1}, {a : 1}, {a : 1} ] const [{ a: item1 }, { a: item2 }, {a: item3}, {a: item4 }] = arr; const newArrOfAs = [item1, item2, item3, item4]; console.log(newArrOfAs); 

Your original code using reduce is better, but even more appropriate would be to use Array.prototype.map , since the input array and output array's items are one-to-one:

 const arr = [ {a : 1}, {a : 1}, {a : 1}, {a : 1} ] const newArrOfAs = arr.map(({ a }) => a); console.log(newArrOfAs); 

Answer 2

You could use the upcoming Array#flatMap

 var array = [{ a: 1 }, { a: 1 }, { a: 1 }, { a: 1 }]; result = array.flatMap(Object.values); console.log(result); 

Answer 3

You would use .map() :

 const a = [ { a: 1 }, { a: 1 }, { a: 1 }, { a: 1 } ]; const b = a.map(val => val.a); console.log(b); 

Answer 4

This should work. You can use foreach or map

 const array = [ {a : 1}, {a : 1}, {a : 1}, {a : 1} ] let newArray = [] array.forEach(function(element) { newArray.push(element.a) }); console.log(newArray) 

Answer 5

You should just use map :

 const arr = [ {a : 1}, {a : 1}, {a : 1}, {a : 1} ]; const res = arr.map(({ a }) => a); console.log(res);