js object destructuring assignment in deep

js object destructuring assignment in deep

obj = {k1: 1, k2: 2, k3: 3};
{k1: 1, k2: 2, k3: 3}
keys = ['k1', 'k2'];
(2) ["k1", "k2"]
const {
  ...keys,
} = obj;
VM380:2 Uncaught SyntaxError: Rest element must be last element
ks = Object.keys(obj);
(3) ["k1", "k2", "k3"]
ks.filter(k => keys.includes(k));
(2) ["k1", "k2"]

根据 keys 结构特定对象的 keys??? entries ??? Map ???

obj = {k1: 1, k2: 2, k3: 3};
// {k1: 1, k2: 2, k3: 3}

Object.entries(obj);
// (3) [Array(2), Array(2), Array(2)]0: (2) ['k1', 1]1: (2) ['k2', 2]2: (2) ['k3', 3]

keys = ['k1', 'k2'];
// (2) ['k1', 'k2']

// Object.entries(obj).filter([k, v] => keys.includes(k));
// Uncaught SyntaxError: Malformed arrow function parameter list

Object.entries(obj).filter(([k, v]) => keys.includes(k));
// (2) [Array(2), Array(2)]0: (2) ['k1', 1]1: (2) ['k2', 2]

Object.fromEntries(Object.entries(obj).filter(([k, v]) => keys.includes(k)));
// {k1: 1, k2: 2}

solution

Object.fromEntries && Object.entries

const obj = {k1: 1, k2: 2, k3: 3};
// {k1: 1, k2: 2, k3: 3}

const keys = ['k1', 'k2'];
// (2) ['k1', 'k2']

Object.fromEntries(Object.entries(obj).filter(([k, v]) => keys.includes(k)));
// {k1: 1, k2: 2}

refs

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment

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