为 JS 对象属性定义名称

Question

我有一个看起来像这样的对象

{taxi: 1, food: 1, cinema: 2, drinks: 2}

我的目标是为这些属性定义一个名称，如下所示：

const expenseCategories = [
  { name: 'taxi', value: 1 },
  { name: 'food', value: 1 },
  { name: 'cinema', value: 2 },
  { name: 'drinks', value: 2},
];

这是我的尝试，我离我想要完成的目标还很远。我知道这很简单，但我很困惑..

  var test = [];

  for (let x in expenseCategories) {
    // expenseCatAmountsObj.push(expenseCategories[x]);
    test.push( Object.defineProperty({}, {name : x}, { value: expenseCategories[x] }) )
  } 

它只是在对象内部返回一个数组

[{…}、{…}、{…}、{…}]

Answer 1

您可以使用Object.entries 和Array.prototype.map

let obj = {taxi: 1, food: 1, cinema: 2, drinks: 2}

let out = Object.entries(obj).map(([name, value]) => ({name, value}));
console.log(out)

Answer 2

我们可以使用 map 遍历对象的键，这将返回一个结果数组：

let categories = {taxi: 1, food: 1, cinema: 2, drinks: 2};

let test = Object.keys(categories).map(k => {
    return { name: k, value: categories[k] }
});

console.log(test);

Answer 3

const temp = {taxi: 1, food: 1, cinema: 2, drinks: 2};

let expenseCategories = Object.keys(temp).map(key => ({name: key, value: temp[key]}));

Answer 4

您可以使用Object.keys

let obj = {taxi: 1, food: 1, cinema: 2, drinks: 2}
let arr = []

let keys = Object.keys(obj)

for (let i = 0; i < keys.length; i++) {
    let key = keys[i]
    arr[i] = {name: key, value: obj[key]}
}

console.log(arr)

Answer 5

你的步骤几乎是正确的——只有Object.defineProperty({}, {name : x}, { value: expenseCategories[x] }) 是不需要的，因为它是做你想做的事情的过于复杂的方式。相反，只需使用对象文字：

var expenseCategories = { taxi: 1, food: 1, cinema: 2, drinks: 2 }

var test = [];

for (let x in expenseCategories) {
  test.push(
    {
      name: x,
      value: expenseCategories[x]
    }
  )
}

console.log(test)

另一种方法是遍历Object.entries 并使用Array#map、destructuring 和short object initialisation syntax 生成一个数组：

var expenseCategories = { taxi: 1, food: 1, cinema: 2, drinks: 2 }

var test = Object.entries(expenseCategories)
  .map(([name, value]) => ({name, value}))

console.log(test)