javascript - 如何通过内部数组中的元素过滤对象数组 - Functional Programming Javascript

Question

我仍在使用函数式编程:.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特征“碳纤维框架”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。使用 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; }

ES6 与 Array#includes作为返回值。

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; }