数组

Question

我有一系列产品，我想过滤所有这些产品。这里的级别也是一个数组，因为我使用了复选框，所以如果用户选择级别1，则应显示级别为1的产品，如果用户再次选择级别2，则应显示级别为1和2的产品。但是我得到的是所有产品而不是选定的级别。

这是我的代码

// sample product data
products = [
{id: "1", sellerLevel: "new", status: "online"},
{id: "1", sellerLevel: "1", status: "offline"},
{id: "1", sellerLevel: "1", status: "offline"},
{id: "1", sellerLevel: "2", status: "online"}
]

function productFilterFromLevel({level}) { // level ["new", "1"]
  return products.filter(function(product) {
    return level.filter(function(lvl) {
      return product.sellerLevel === lvl;
    });
  });
} 

Answer 1

您可以将Array.includes与过滤器一起使用

const productFilterFromLevel = ({level}, products) => products
  .filter(item => level.includes(item.sellerLevel))

或没有包含你可以像这样过滤键

const productFilterFromLevel = function({level}, products) {
  return products.filter(function(product) {
    return level.indexOf(product.sellerLevel) !== -1
  })
}

正如您所看到的，includes版本更清晰，但您始终可以创建自己的包含功能：

const arrayIncludes = function(array, item) {
  return array.indexOf(item) !== -1
}

Answer 2

你有一个对象数组，这是Array.filter的一个很好的用例。

// sample product data
products = [
{id: "1", sellerLevel: "new", status: "online"},
{id: "1", sellerLevel: "1", status: "offline"},
{id: "1", sellerLevel: "1", status: "offline"},
{id: "1", sellerLevel: "2", status: "online"}
]

function filter(products, matches) {
  return products.filter(product => {
    return matches.includes(product.sellerLevel);
  });
}

console.log(filter(products, ['new', '1']));

// [
//   {id: "1", sellerLevel: "new", status: "online"},
//   {id: "1", sellerLevel: "1", status: "offline"},
//   {id: "1", sellerLevel: "1", status: "offline"}
// ]

https://jsfiddle.net/persianturtle/fL8eupoz/3/

Answer 3

这不像简单匹配那么简单，因为您需要比较sellerLevel：

function productFilterFromLevel(level) { // level ["new", "1"]
  return products.filter(function(product) {
    for (var i = 0; i < level.length; i++) {
      if (level[i] === 'new') {
        return product.sellerLevel === 'new'
      }
      return +product.sellerLevel <= +level[i]
    }
  });
} 

Answer 4

// sample product data
products = [{
  id: "1",
  sellerLevel: "new",
  status: "online"
}, {
  id: "1",
  sellerLevel: "1",
  status: "offline"
}, {
  id: "1",
  sellerLevel: "1",
  status: "offline"
}, {
  id: "1",
  sellerLevel: "2",
  status: "online"
}]

function productFilterFromLevel(level) {
  return products.filter(function(product) {
    return level.indexOf(product.sellerLevel) != -1;
  });
}

console.log(productFilterFromLevel(["new", "1"]));