Question

我正在尝试在以下部分JSON中访问“ 15.00”，但是如果我使用object.shipping.rates.rate.amount，则会出现“未定义不是对象”错误。我认为令我困扰的是JSON包含两个“ region_code”，当我调用该属性时，Javascript不知道该给我哪个。而且我不知道该如何告诉我与“ US_CON” region_code关联的那个。我该如何指定？谢谢。

"shipping": {
        "free_expedited_shipping": false,
        "local": false,
        "rates": [
          {
            "region_code": "US_CON",
            "rate": {
              "amount": "15.00",
              "amount_cents": 1500,
              "currency": "USD",
              "symbol": "$",
              "display": "$15"
            }
          },
          {
            "region_code": "XX",
            "rate": {
              "amount": "50.00",
              "amount_cents": 5000,
              "currency": "USD",
              "symbol": "$",
              "display": "$50"
            }

Answer 1

object.shipping.rates是一个数组。您将无法像这样访问它。

请使用索引或循环。

索引

console.log(object.shipping.rates[0].rate.amount)

循环

Object.keys(object.shipping.rates).map(key => {
   console.log(object.shipping.rates[key].rate.amount)
})

Answer 2

您可以使用find来获得region_code为US_CON的区域。

var shipping = {
  "free_expedited_shipping": false,
  "local": false,
  "rates": [
    {
      "region_code": "US_CON",
      "rate": {
        "amount": "15.00",
        "amount_cents": 1500,
        "currency": "USD",
        "symbol": "$",
        "display": "$15"
      }
    },
    {
      "region_code": "XX",
      "rate": {
        "amount": "50.00",
        "amount_cents": 5000,
        "currency": "USD",
        "symbol": "$",
        "display": "$50"
      }
    }
  ]
};

const region = shipping.rates.find(r => r.region_code == 'US_CON');
console.log(region.rate.amount);

Javascript：使用相同的名称访问JSON属性？

2 个答案: