如何映射嵌套对象的数组？

Question

I have the following JSON response:

{
    "fruits": [
        {
            "name": "apple",
            "prices": [
                {
                    "small": 2,
                    "medium": 3,
                    "large": 5
                }
            ]
        },
        {
            "name": "banana",
            "prices": [
                {
                    "small": 1,
                    "medium": 3,
                    "large": 4
                }
            ]
        }
    ]
}

I want to map it to a new array, so that I can get the "price.small" of each fruit:

$scope.new_data = $scope.fruits.map(function(fruit){
    return {
        name: fruit.name,
        price_small: fruit.prices.small
    };
});

But it's not working

Answer 1

You need get first element in Array fruit.prices[0].small because fruit.prices is Array that contains only one element and this element is Object

 var $scope = {}; $scope.fruits = [{ "name": "apple", "prices": [{ "small": 2, "medium": 3, "large": 5 }] }, { "name": "banana", "prices": [{ "small": 1, "medium": 3, "large": 4 }] }, { "name": "mango", "prices": { "small": 100, "medium": 3, "large": 4 } }]; $scope.new_data = $scope.fruits.map(function(fruit){ return { name: fruit.name, price_small: Array.isArray(fruit.prices) ? fruit.prices[0].small : (fruit.prices || {}).small || 0 }; }); console.log($scope.new_data); 

Update:

fruit.prices can be Object or Array with one element that't why in example there is condition to check it ( Array.isArray )