[英]Looping and extracting values from JSON and pushing to Arrays
我有一個JSON文件,我需要在其中訪問其中一個值,該值是一個包含許多鍵和值的對象,這些鍵和值是進一步的對象。 像這樣:
"lineChart": {
"Fri Jul 28, 2017": {
"renewalFee_EUR": 1165,
"extensionFee_EUR": 0,
"renewalFee_USD": 5941.5,
"extensionFee_USD": 0,
"processingFee_USD": 25,
"expressFee_USD": 0,
"urgentFee_USD": 0,
"latePayPenalty_USD": 0,
"fxRate": 5.1,
"subTotal_USD": 5966.5
},
"Tue Aug 1, 2017": {
"renewalFee_EUR": 1165,
"extensionFee_EUR": 0,
"renewalFee_USD": 2411.55,
"extensionFee_USD": 0,
"processingFee_USD": 25,
"expressFee_USD": 0,
"urgentFee_USD": 0,
"latePayPenalty_USD": 0,
"fxRate": 2.07,
"subTotal_USD": 2436.55
}
}
我已經能夠將鍵值即Fri Jul 28, 2017
年Fri Jul 28, 2017
在一個數組中,該數組用於將數據傳遞到視圖中的圖表。 這部分工作正常。
var caLine = vm.graph.lineChart;
// THIS STORES THE RETURNED VALUE(GRAPH DATA) FROM A REST REQUEST
//IN MY ROUTER FOLDER (USING ANGULARJS)
lineLabelArr = [];
for (var prop in caLine) {
if (caLine.hasOwnProperty(prop)) {
lineLabelArr.push(prop)
}
}
vm.labels = lineLabelArr; //VM.LABELS IS UED TO BIND DATA TO THE CHART'S DIRECTIVES
我只需要JSON文件中subTotal_USD
下的數據subTotal_USD
在圖表中顯示為數據。
題
如何遍歷lineChart
對象中的每個屬性,如何從subTotal_USD
鍵中提取值,並將其存儲在可用於在圖表中顯示數據的數組中? 我覺得這讓事情變得復雜了。
您已經有了一系列鍵,可以使用forEach
, map
, reduce
等來循環。
您可以使用map
在鍵數組之外創建一個新數組:
const lineChart = {"Fri Jul 28, 2017":{renewalFee_EUR:1165,extensionFee_EUR:0,renewalFee_USD:5941.5,extensionFee_USD:0,processingFee_USD:25,expressFee_USD:0,urgentFee_USD:0,latePayPenalty_USD:0,fxRate:5.1,subTotal_USD:5966.5},"Tue Aug 1, 2017":{renewalFee_EUR:1165,extensionFee_EUR:0,renewalFee_USD:2411.55,extensionFee_USD:0,processingFee_USD:25,expressFee_USD:0,urgentFee_USD:0,latePayPenalty_USD:0,fxRate:2.07,subTotal_USD:2436.55}}; const lineLabelArr = []; for (var prop in lineChart) { if (lineChart.hasOwnProperty(prop)) { lineLabelArr.push(prop) } } console.log( lineLabelArr.map(key => lineChart[key].subTotal_USD) );
當然,有很多方法可以遍歷對象的鍵。 就個人而言,我寧願做一個循環:
const lineChart = {"Fri Jul 28, 2017":{renewalFee_EUR:1165,extensionFee_EUR:0,renewalFee_USD:5941.5,extensionFee_USD:0,processingFee_USD:25,expressFee_USD:0,urgentFee_USD:0,latePayPenalty_USD:0,fxRate:5.1,subTotal_USD:5966.5},"Tue Aug 1, 2017":{renewalFee_EUR:1165,extensionFee_EUR:0,renewalFee_USD:2411.55,extensionFee_USD:0,processingFee_USD:25,expressFee_USD:0,urgentFee_USD:0,latePayPenalty_USD:0,fxRate:2.07,subTotal_USD:2436.55}}; const labels = []; const subTotals = []; Object.keys(lineChart).forEach(day => { const dayData = lineChart[day]; labels.push(day); subTotals.push(dayData.subTotal_USD); }); console.log("Labels:", labels); console.log("subTotals:", subTotals);
for(var i = 0; i < caLine.length; i++) {
var datObj = caLine[i];
if (datObj != null) {
var subTotoalUSD = datObj["subTotal_USD"];
}
}
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