英文:
Pull data from sub object within array
问题
我看不出我在这里做错了什么，但我在控制台中得到了“undefined”。希望您可以在代码片段中看到，我传递了一些JSON数据。这实际上是2个商店的数据，并且每个商店都有一些交易。我可以取回顶层数据，但我很难从交易行级别取回数据。
每当我尝试引用事务行中的某些内容时，就会出现问题。有人可以指导我如何引用数组的这一部分吗？
非常感谢
/// 假的JSON数据，已字符串化并放在顶部 ///const inputData = "[{\r\n\t\t\"transaction\": 1,\r\n\t\t\"store\": 1,\r\n\t\t\"transactionLines\": [{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 3,\r\n\t\t\t\t\"lineValue\": 25\r\n\t\t\t},\r\n\r\n\t\t\t{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 2,\r\n\t\t\t\t\"lineValue\": 50\r\n\t\t\t},\r\n\t\t\t{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 1,\r\n\t\t\t\t\"lineValue\": 100\r\n\t\t\t}\r\n\t\t]\r\n\t},\r\n\t{\r\n\t\t\"transaction\": 2,\r\n\t\t\"store\": 2,\r\n\t\t\"transactionLines\": [{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 2,\r\n\t\t\t\t\"lineValue\": 50\r\n\t\t\t},\r\n\t\t\t{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 1,\r\n\t\t\t\t\"lineValue\": 100\r\n\t\t\t}\r\n\t\t]\r\n\t}\r\n]";const input = JSON.parse(inputData);var total = 0;// 第一个“for循环”遍历输入数据并列出交易for (let i = 0; i < input.length; i++) {console.log(input[i].transaction);// 第二个“for循环”在交易循环内部。它遍历上面循环的交易数据并列出交易for (let j = 0; j < input[i].transactionLines.length; j++) {// 通过将行值添加到现有总值来增加总值total = total + input[i].transactionLines[j].lineValue;console.log("Transaction ID = " + input[i].transaction + " 循环 x " + j + ": 新总值 = " + total);}}
希望这能帮助您解决问题。
英文:
I can't see what I'm doing wrong here but I'm getting "undefined" back in my console.
Hopefully you can see in the snippet I am passing in some JSON data. This effectively 2 stores worth of data and against each store there are a few transactions. I can pull back the top level data but I'm struggling to pull back data from the transaction line level.
Its whenever I try to reference something from within my transaction lines. Can anyone point me in the right direction as to how I'm referencing that part of my array?
Many thanks
<!-- begin snippet: js hide: false console: true babel: false -->
<!-- language: lang-js -->
///Dummy JSON Data Stringified and put in the top /////////const inputData= "[{\r\n\t\t\"transaction\": 1,\r\n\t\t\"store\": 1,\r\n\t\t\"transactionLines\": [{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 3,\r\n\t\t\t\t\"lineValue\": 25\r\n\t\t\t},\r\n\r\n\t\t\t{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 2,\r\n\t\t\t\t\"lineValue\": 50\r\n\t\t\t},\r\n\t\t\t{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 1,\r\n\t\t\t\t\"lineValue\": 100\r\n\t\t\t}\r\n\t\t]\r\n\t},\r\n\t{\r\n\t\t\"transaction\": 2,\r\n\t\t\"store\": 2,\r\n\t\t\"transactionLines\": [{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 2,\r\n\t\t\t\t\"lineValue\": 50\r\n\t\t\t},\r\n\t\t\t{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 1,\r\n\t\t\t\t\"lineValue\": 100\r\n\t\t\t}\r\n\t\t]\r\n\t}\r\n]"const input = JSON.parse(inputData);var total = 0;////// First "For Loop" goes through input data /////////// and lists transactions ///////////////////////for(let i=0;i<input.length;i++){console.log(input[i].transaction);///////// 2nd "For Loop" is inside the transaction loop. ///////////////// This goes through transaction data from the above loop ////////// and lists transactions ///////////////////////////////for(let j=0;j<input[i].transactionLines.length;j++){///////// Increase the total by adding the line value to the ////////////// existing total ////////////////////////////////////////total = total+input[i].lineValueconsole.log(input[i].transactionLines.lineId);console.log("Transaction ID = "+input[i].transaction+" loop x "+j+": New Total = "+input[i].transactionLines.transactionId);}}
<!-- language: lang-html -->
<div><h1>Sample Json Data Shown Below</h1><h2>Check console for outputs</h2></div><xmp>[{"transaction": 1,"store": 1,"transactionLines": [{"transactionId": 1,"lineId": 3,"lineValue": 25},{"transactionId": 1,"lineId": 2,"lineValue": 50},{"transactionId": 1,"lineId": 1,"lineValue": 100}]},{"transaction": 2,"store": 2,"transactionLines": [{"transactionId": 1,"lineId": 2,"lineValue": 50},{"transactionId": 1,"lineId": 1,"lineValue": 100}]}]</xmp>
<!-- end snippet -->
答案1
得分: 1
你忘记使用 j 变量。
///虚拟 JSON 数据已被字符串化并放在顶部//////const inputData = "[{\r\n\t\t\"transaction\": 1,\r\n\t\t\"store\": 1,\r\n\t\t\"transactionLines\": [{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 3,\r\n\t\t\t\t\"lineValue\": 25\r\n\t\t\t},\r\n\r\n\t\t\t{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 2,\r\n\t\t\t\t\"lineValue\": 50\r\n\t\t\t},\r\n\t\t\t{\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 1,\r\n\t\t\t\t\"lineValue\": 100\r\n\t\t\t}\r\n\t\t]\r\n\t},\r\n\t{\r\n\t\t\"transaction\": 2,\r\n\t\t\"store\": 2,\r\n\t\t\"transactionLines\": [{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 2,\r\n\t\t\t\t\"lineValue\": 50\r\n\t\t\t},\r\n\t\t\t{\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 1,\r\n\t\t\t\t\"lineValue\": 100\r\n\t\t\t}\r\n\t\t]\r\n\t}\r\n]";const input = JSON.parse(inputData);var total = 0;////// 第一个 “For Loop” 遍历输入数据 /////////// 并列出交易 ///////////////////////for (let i = 0; i < input.length; i++) {console.log(input[i].transaction);///////// 第二个 “For Loop” 在交易循环内部。 ///////////////// 这遍历了上面循环中的交易数据 ////////// 并列出交易 ///////////////////////////////for (let j = 0; j < input[i].transactionLines.length; j++) {///////// 通过将行值添加到现有总和来增加总数 ////////////////////////////////////////total = total + input[i].transactionLines[j].lineValueconsole.log(input[i].transactionLines[j].lineId);console.log("Transaction ID = " + input[i].transaction + " loop x " + j + ": New Total = " + input[i].transactionLines[j].transactionId);}}
<div><h1>以下是示例的 Json 数据</h1><h2>请查看控制台输出</h2></div><xmp>[{ "transaction": 1, "store": 1, "transactionLines": [{ "transactionId": 1, "lineId": 3, "lineValue": 25 }, { "transactionId": 1, "lineId": 2, "lineValue": 50 }, { "transactionId": 1, "lineId": 1, "lineValue": 100 } ] }, { "transaction": 2, "store": 2,"transactionLines": [{ "transactionId": 1, "lineId": 2, "lineValue": 50 }, { "transactionId": 1, "lineId": 1, "lineValue": 100 } ] } ]</xmp>
英文:
You forgot to use j variable
<!-- begin snippet: js hide: false console: true babel: false -->
<!-- language: lang-js -->
///Dummy JSON Data Stringified and put in the top /////////const inputData = "[{\r\n\t\t\"transaction\": 1,\r\n\t\t\"store\": 1,\r\n\t\t\"transactionLines\": [{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 3,\r\n\t\t\t\t\"lineValue\": 25\r\n\t\t\t},\r\n\r\n\t\t\t{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 2,\r\n\t\t\t\t\"lineValue\": 50\r\n\t\t\t},\r\n\t\t\t{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 1,\r\n\t\t\t\t\"lineValue\": 100\r\n\t\t\t}\r\n\t\t]\r\n\t},\r\n\t{\r\n\t\t\"transaction\": 2,\r\n\t\t\"store\": 2,\r\n\t\t\"transactionLines\": [{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 2,\r\n\t\t\t\t\"lineValue\": 50\r\n\t\t\t},\r\n\t\t\t{\r\n\t\t\t\t\"transactionId\": 1,\r\n\t\t\t\t\"lineId\": 1,\r\n\t\t\t\t\"lineValue\": 100\r\n\t\t\t}\r\n\t\t]\r\n\t}\r\n]"const input = JSON.parse(inputData);var total = 0;////// First "For Loop" goes through input data /////////// and lists transactions ///////////////////////for (let i = 0; i < input.length; i++) {console.log(input[i].transaction);///////// 2nd "For Loop" is inside the transaction loop. ///////////////// This goes through transaction data from the above loop ////////// and lists transactions ///////////////////////////////for (let j = 0; j < input[i].transactionLines.length; j++) {///////// Increase the total by adding the line value to the ////////////// existing total ////////////////////////////////////////total = total + input[i].lineValueconsole.log(input[i].transactionLines[j].lineId);console.log("Transaction ID = " + input[i].transaction + " loop x " + j + ": New Total = " + input[i].transactionLines[j].transactionId);}}
<!-- language: lang-html -->
<div><h1>Sample Json Data Shown Below</h1><h2>Check console for outputs</h2></div><xmp>[{ "transaction": 1, "store": 1, "transactionLines": [{ "transactionId": 1, "lineId": 3, "lineValue": 25 }, { "transactionId": 1, "lineId": 2, "lineValue": 50 }, { "transactionId": 1, "lineId": 1, "lineValue": 100 } ] }, { "transaction": 2, "store": 2,"transactionLines": [{ "transactionId": 1, "lineId": 2, "lineValue": 50 }, { "transactionId": 1, "lineId": 1, "lineValue": 100 } ] } ]</xmp>
<!-- end snippet -->
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