如何总结json数组

Question

如何使用jQuery对这样的JSON数组元素进行求和：

"taxes": [ { "amount": 25, "currencyCode": "USD", "decimalPlaces": 0,"taxCode": "YRI",
{ "amount": 25, "currencyCode": "USD", "decimalPlaces": 0,"taxCode": "YRI",
{ "amount": 10, "currencyCode": "USD", "decimalPlaces": 0,"taxCode": "YRI",}],

结果应为：

totalTaxes = 60

Answer 1

使用JSON 101

var foo = {
        taxes: [
            { amount: 25, currencyCode: "USD", decimalPlaces: 0, taxCode: "YRI"},
            { amount: 25, currencyCode: "USD", decimalPlaces: 0, taxCode: "YRI"},
            { amount: 10, currencyCode: "USD", decimalPlaces: 0, taxCode: "YRI"}
        ]
    },
    total = 0,  //set a variable that holds our total
    taxes = foo.taxes,  //reference the element in the "JSON" aka object literal we want
    i;
for (i = 0; i < taxes.length; i++) {  //loop through the array
    total += taxes[i].amount;  //Do the math!
}
console.log(total);  //display the result

Answer 2

如果你真的必须使用jQuery，你可以这样做：

var totalTaxes = 0;

$.each(taxes, function () {
    totalTaxes += this.amount;
});

或者您可以在支持它的浏览器中使用ES5 reduce功能：

totalTaxes = taxes.reduce(function (sum, tax) {
    return sum + tax.amount;
}, 0);

或者只是像@ epascarello的答案那样使用for循环......