基于多个参数减少的对象数组

Question

需要减少对象数组以返回同名的最高值。

需要以下内容，

[
    {
        name: 'a',
        value: 20
    },
    {
        name: 'a',
        value: 80
    },
    {
        name: 'b',
        value: 90
    },
    {
        name: 'b',
        value: 50
    }
]

返回

[
    {
        name: 'a',
        value: 80
    },
    {
        name: 'b',
        value: 90
    }
]

我有一个解决方案，但似乎有点太多，想知道是否有更直接的方法来实现它？

以下是我能想到的解决方案：

var toReduce = [
    {
        'name': 'a',
        'value': 20
    },
    {
        'name': 'a',
        'value': 80
    },
    {
        'name': 'b',
        'value': 90
    },
    {
        'name': 'b',
        'value': 50
    }
];


function arrayReducer(arrayToReduce) {
    // Created an object separating by name
    let reduced = arrayToReduce.reduce((accumulator, currentValue) => {
        (accumulator[currentValue.name] =
            accumulator[currentValue.name] || []).push(currentValue);
        return accumulator;
    }, {});
    // Reduce object to the highest value
    for (let quotes of Object.keys(reduced)) {
        reduced[quotes] = reduced[quotes].reduce(
            (accumulator, currentValue) => {
                return accumulator && accumulator.value > currentValue.value
                    ? accumulator
                    : currentValue;
            }
        );
    }
    // return only object values
    return Object.values(reduced);
}

console.log(arrayReducer(toReduce));

Answer 1

您可以在

reduce()

期间计算最大值，而不是在单独的循环中计算。

var toReduce = [{
    'name': 'a',
    'value': 20
  },
  {
    'name': 'a',
    'value': 80
  },
  {
    'name': 'b',
    'value': 90
  },
  {
    'name': 'b',
    'value': 50
  }
];


function arrayReducer(arrayToReduce) {
  // Created an object separating by name
  let reduced = arrayToReduce.reduce((accumulator, currentValue) => {
    accumulator[currentValue.name] = {
      name: currentValue.name,
      value: accumulator.hasOwnProperty(currentValue.name) ? Math.max(accumulator[currentValue.name].value, currentValue.value) : currentValue.value
    };
    return accumulator;
  }, {});
  // return only object values
  return Object.values(reduced);
}

console.log(arrayReducer(toReduce));