javascript - 如果条件存在则链接多个过滤器

Question

我正在尝试链接两个过滤器，基于两个参数范围(数组)，这些参数也可能为空，因此 f.ex. speedlimit=[]

var speedfilter =[240,300]
var pricefilter = [80,120]
var cars = [
  {name:'Ferrari', maxspeed:240, price: 100},
  {name:'Porsche', maxspeed:220, price: 90},
  {name:'Bugatti', maxspeed:300, price: 500}
  ];


if (speedfilters) {
  return cars.filter(function (car) {
    return car.maxspeed >= speedfilter[0] && car.maxspeed <= speedfilter[1];
  })
} else if (pricefilter) {
  return cars.filter(function (car) {
    return car.price >= pricefilter[0] && car.price <= pricefilter[1];
  })
}
else return cars

上例中的结果应输出{name:'Ferrari', speed:240, Price: 100}

使用 javascript filter 来实现这一点的方法是什么？提前致谢!

Answer 1

您可以通过原型(prototype)继承创建一个 filterCar 方法

Array.prototype.filterCar = function(feature, range) {
   return this.filter((el) => {
     // is the range defined?
     if (!!range.length) {
        return el[feature] >= range[0] && el[feature] <= range[1];
     }
     else {
        return true;
     }
   })
};


var cars = [
  {name:'Ferrari', speed:240, price: 100},
  {name:'Porsche', speed:220, price: 90},
  {name:'Bugatti', speed:300, price: 500}
 ];

var result1 = cars.filterCar('speed', [240, 300])
                  .filterCar('price', [80, 120]));

var result2 = cars.filterCar('speed', [ ])
                  .filterCar('price', [80, 120]));



console.log(result1); // [{name: "Ferrari", speed: 240, price: 100}]

console.log(result2); /* [{name: "Ferrari", speed: 240, price: 100}, 
                         {name: "Porsche", speed: 220, price: 90}] */