我正在尝试根据两个也可能为空的参数范围(数组)链接两个过滤器,因此f.ex可能会出现。 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
上面示例中的结果应输出{name:'Ferrari', speed:240, price: 100}
使用JavaScript filter
的方式是什么?预先感谢!
答案 0 :(得分:2)
您可以通过原型继承创建一个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}] */
答案 1 :(得分:1)
您可以将过滤器包装成可重复使用的方法,这可以说明过滤器不可用。
function filterCars(carsArray, property, rangeArray) {
// if rangeArray is not supplied, or is empty, just return the unfiltered input
if(!rangeArray|| rangeArray.length === 0) {
return carsArray;
}
// otherwise filter according to logic
return carsArray.filter(car => car[property] >= rangeArray[0] && car[property] <= rangeArray[1]);
}
可以将其链接起来,或者为了提高可读性依次调用:
function filterCars(carsArray, property, rangeArray) {
if(!rangeArray|| rangeArray.length === 0) {
return carsArray;
}
return carsArray.filter(car => car[property] >= rangeArray[0] && car[property] <= rangeArray[1]);
}
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}
];
cars = filterCars(cars,"maxspeed",speedfilter);
cars = filterCars(cars,"price",pricefilter);
console.log(cars);