函数获取json到javascript中的字符串的值

Question

我需要帮助来获取一个函数的json值，并将该函数的值传递给控制台，但现在我是recient var=undefined，请按照下面的代码操作，谢谢

var Site = {
    baseUrl: "https://www.usereserva.com/",
    visitUrl: "https://cloud-commerce-visit.oracleoutsourcing.com/"
}

var prodAPI = Site.baseUrl + "ccstoreui/v1/products/" + prodId;
var prodId = '0058597';

console.log("============= SCRIPT CALLCAPRODUCT ==============");
console.log("url API: " + prodAPI);
console.log("Id buscada: " + prodId);

var request = require('request');
var price;

function prodPrice() {
    request(Site.baseUrl + "ccstoreui/v1/prices/" + prodId, function (error, response, body) {
        var corpo = JSON.parse(body);
        price = corpo['sale'];
        console.log(price);  // result 169
    });
}
console.log("preço:  " + prodPrice());
console.log("Requisição CALLPRODUCT foi bem sucedida");
console.log("================================================");  

Answer 1

是的，您是在将值赋给prodId之前使用prodId变量。 这将返回错误。 这里将进行吊装。 您的代码将编译为

  var Site = {
    baseUrl: "https://www.usereserva.com/",
    visitUrl: "https://cloud-commerce-visit.oracleoutsourcing.com/"
}
var prodId ; 
var prodAPI = Site.baseUrl + "ccstoreui/v1/products/" + prodId; // so here 
// prodId is undefined,thats why error. 
prodId = '0058597';

console.log("============= SCRIPT CALLCAPRODUCT ==============");
console.log("url API: " + prodAPI);
console.log("Id buscada: " + prodId);

var request = require('request');
var price;

function prodPrice() {
    request(Site.baseUrl + "ccstoreui/v1/prices/" + prodId, function (error, response, body) {
        var corpo = JSON.parse(body);
        price = corpo['sale'];
        console.log(price);  // result 169
    });
}
console.log("preço:  " + prodPrice());
console.log("Requisição CALLPRODUCT foi bem sucedida");
console.log("================================================");

首先初始化并赋值prodId变量，然后使用它

var prodId =  "0058597";
var prodAPI = Site.baseUrl + "ccstoreui/v1/products/" + prodId; 

另一种情况是，您没有从prodPrice()方法返回任何值，默认返回值是undefined。 方法返回所需的值。

请阅读有关吊装的Java文字。 这将有助于提升