如何通过内部数组中的元素过滤对象数组 - JavaScript 函数式编程

Question

我仍在通过函数式编程：.forEach()、.map()、.filter()、.reduce()。

我正在应对新的挑战。

var bikes = [
   {name: 'Cinelli Bolt', price: '2000', age: 1, singlespeed: 'yes', features: ['tubeless tires', 'disk brakes', 'carbon frame']},
   {name: 'Cinelli Mash', price: '1700', age: 3, singlespeed: 'yes', features: ['gatorskin tyres', 'sram drivetrain', 'steel frame']},
   {name: 'Specialized Langster', price: '1000', age: 1, singlespeed: 'no', features: ['two speed enclosed hub', 'bullbars', 'carbon frame']}
 ]; 

我正在尝试通过特定功能“碳框架”过滤阵列。我正在考虑使用过滤器，但我对在 key.value 对中调用该功能感到困惑。

var justCarbonBikes = bikes.filter(function(bike) {
  return bike.features['carbon frame'];
});

预期结果应该修改原始数组：

var bikes = [
   {name: 'Cinelli Bolt', price: '2000', age: 1, singlespeed: 'yes', features: ['tubeless tires', 'disk brakes', 'carbon frame']},
   {name: 'Specialized Langster', price: '1000', age: 1, singlespeed: 'no', features: ['two speed enclosed hub', 'bullbars', 'carbon frame']}
 ]; 

Answer 1

你快到了。通过Array#indexOf检查索引，您可以将其用作返回值。

return bike.features.indexOf('carbon frame') + 1;

var bikes = [{ name: 'Cinelli Bolt', price: '2000', age: 1, singlespeed: 'yes', features: ['tubeless tires', 'disk brakes', 'carbon frame'] }, { name: 'Cinelli Mash', price: '1700', age: 3, singlespeed: 'yes', features: ['gatorskin tyres', 'sram drivetrain', 'steel frame'] }, { name: 'Specialized Langster', price: '1000', age: 1, singlespeed: 'no', features: ['two speed enclosed hub', 'bullbars', 'carbon frame'] }],
    justCarbonBikes = bikes.filter(function(bike) {
        return bike.features.indexOf('carbon frame') + 1;
    }),
    bikesWithoutCarbon = bikes.filter(function(bike) {
        return bike.features.indexOf('carbon frame') === -1;
    });

console.log(justCarbonBikes);
console.log(bikesWithoutCarbon);

.as-console-wrapper { max-height: 100% !important; top: 0; }

以Array#includes 作为返回值的ES6。

var bikes = [{ name: 'Cinelli Bolt', price: '2000', age: 1, singlespeed: 'yes', features: ['tubeless tires', 'disk brakes', 'carbon frame'] }, { name: 'Cinelli Mash', price: '1700', age: 3, singlespeed: 'yes', features: ['gatorskin tyres', 'sram drivetrain', 'steel frame'] }, { name: 'Specialized Langster', price: '1000', age: 1, singlespeed: 'no', features: ['two speed enclosed hub', 'bullbars', 'carbon frame'] }],
    justCarbonBikes = bikes.filter(b => b.features.includes('carbon frame')),
    bikesWithoutCarbon = bikes.filter(b => !b.features.includes('carbon frame'));

console.log(justCarbonBikes);
console.log(bikesWithoutCarbon);

.as-console-wrapper { max-height: 100% !important; top: 0; }

Answer 2

这是一种解决方案，您可以遍历过滤器函数中的特征，如果找到碳框则返回

var justCarbonBikes = bikes.filter(function(bike) {
  for(let i of bike.features){
    if(i == 'carbon frame'){
      return bike
    }
  }
});