JS - 它是什么类型的对象，我怎样才能访问它
问题描述：
我正在玩reactjs并且在处理对象时遇到问题。目的是如下：JS - 它是什么类型的对象，我怎样才能访问它
export default [
{
"Type": "Buy",
"Price": 0.00226752,
"Amount": 55.95995977,
"Total": 0.12689032
},
{
"Type": "Buy",
"Price": 0.00226752,
"Amount": 146.1,
"Total": 0.33128467
},
{
"Type": "Buy",
"Price": 0.00226684,
"Amount": 150,
"Total": 0.340026
},
{
"Type": "Buy",
"Price": 0.00226684,
"Amount": 26.79415765,
"Total": 0.06073806
},
{
"Type": "Buy",
"Price": 0.00226684,
"Amount": 4.25269162,
"Total": 0.00964017
},
{
"Type": "Buy",
"Price": 0.00226659,
"Amount": 25.79415765,
"Total": 0.05846477
},
{
"Type": "Buy",
"Price": 0.00225784,
"Amount": 4.48789501,
"Total": 0.01013294
},
{
"Type": "Buy",
"Price": 0.00226659,
"Amount": 1,
"Total": 0.00226659
},
{
"Type": "Buy",
"Price": 0.00226663,
"Amount": 225,
"Total": 0.50999175
},
{
"Type": "Buy",
"Price": 0.00226662,
"Amount": 113.4736507,
"Total": 0.25720164
},
{
"Type": "Buy",
"Price": 0.00226659,
"Amount": 26.79415765,
"Total": 0.06073136
},
{
"Type": "Buy",
"Price": 0.00226651,
"Amount": 57.98798342,
"Total": 0.13143034
},
{
"Type": "Buy",
"Price": 0.00226649,
"Amount": 40.19123647,
"Total": 0.09109303
},
{
"Type": "Buy",
"Price": 0.00224958,
"Amount": 11.83690383,
"Total": 0.02662806
},
{
"Type": "Sell",
"Price": 0.00241238,
"Amount": 838,
"Total": 2.02157444
},
{
"Type": "Buy",
"Price": 0.00231078,
"Amount": 9.95795791,
"Total": 0.02301064
},
{
"Type": "Sell",
"Price": 0.0025,
"Amount": 4.1999832,
"Total": 0.01049995
},
{
"Type": "Sell",
"Price": 0.0025,
"Amount": 4.99998,
"Total": 0.01249995
},
{
"Type": "Buy",
"Price": 0.00226702,
"Amount": 3.63623022,
"Total": 0.0082434
},
{
"Type": "Buy",
"Price": 0.00226702,
"Amount": 2.14933238,
"Total": 0.00487257
},
{
"Type": "Buy",
"Price": 0.00226702,
"Amount": 15,
"Total": 0.0340053
},
{
"Type": "Buy",
"Price": 0.00226702,
"Amount": 56.80528353,
"Total": 0.12877871
},
{
"Type": "Buy",
"Price": 0.00227634,
"Amount": 76.88367619,
"Total": 0.17501338
},
{
"Type": "Sell",
"Price": 0.0000141,
"Amount": 12444,
"Total": 0.17546011
},
{
"Type": "Buy",
"Price": 0.0000141,
"Amount": 12131.09257,
"Total": 0.1710484
},
{
"Type": "Buy",
"Price": 0.00001409,
"Amount": 344.0847392,
"Total": 0.00484815
},
{
"Type": "Buy",
"Price": 0.00249461,
"Amount": 154.2853438,
"Total": 0.38488176
},
{
"Type": "Buy",
"Price": 0.00249461,
"Amount": 33.72938801,
"Total": 0.08414166
},
{
"Type": "Buy",
"Price": 0.00246953,
"Amount": 340.8737595,
"Total": 0.84179797
},
{
"Type": "Buy",
"Price": 0.00246953,
"Amount": 90.36231511,
"Total": 0.22315244
},
{
"Type": "Buy",
"Price": 0.00246952,
"Amount": 55.17093479,
"Total": 0.13624572
},
{
"Type": "Buy",
"Price": 0.00246764,
"Amount": 5.75660177,
"Total": 0.01420522
},
{
"Type": "Buy",
"Price": 0.00245929,
"Amount": 4.1587629,
"Total": 0.0102276
},
{
"Type": "Sell",
"Price": 0.00252904,
"Amount": 37.42985716,
"Total": 0.0946616
},
{
"Type": "Sell",
"Price": 0.00252904,
"Amount": 0.59310808,
"Total": 0.00149999
},
{
"Type": "Sell",
"Price": 0.00252904,
"Amount": 1.97703476,
"Total": 0.00499999
},
{
"Type": "Sell",
"Price": 0.00252902,
"Amount": 446.0229574,
"Total": 1.12800097
},
{
"Type": "Sell",
"Price": 0.00252903,
"Amount": 1.97704258,
"Total": 0.00499999
},
{
"Type": "Sell",
"Price": 0.00259459,
"Amount": 38.54173491,
"Total": 0.09999999
},
{
"Type": "Sell",
"Price": 0.00259483,
"Amount": 105.9381622,
"Total": 0.27489152
},
{
"Type": "Sell",
"Price": 0.00259484,
"Amount": 0.03853803,
"Total": 0.0001
},
{
"Type": "Sell",
"Price": 0.00259484,
"Amount": 0.03853803,
"Total": 0.0001
},
{
"Type": "Sell",
"Price": 0.00259485,
"Amount": 1.91102375,
"Total": 0.00495881
},
{
"Type": "Sell",
"Price": 0.00259459,
"Amount": 2,
"Total": 0.00518918
},
{
"Type": "Sell",
"Price": 0.00259464,
"Amount": 1.90549392,
"Total": 0.00494407
},
{
"Type": "Sell",
"Price": 0.00259465,
"Amount": 28.65568722,
"Total": 0.07435147
},
{
"Type": "Buy",
"Price": 0.01740491,
"Amount": 0.20683711,
"Total": 0.00359998
},
{
"Type": "Buy",
"Price": 0.00238916,
"Amount": 79.70696671,
"Total": 0.19043269
},
{
"Type": "Buy",
"Price": 0.00237524,
"Amount": 37.90636505,
"Total": 0.09003671
},
{
"Type": "Buy",
"Price": 0.00237524,
"Amount": 2.00494017,
"Total": 0.00476221
},
{
"Type": "Buy",
"Price": 0.00237524,
"Amount": 18.57724489,
"Total": 0.04412541
},
{
"Type": "Sell",
"Price": 0.00585,
"Amount": 56.99961222,
"Total": 0.33344773
},
{
"Type": "Sell",
"Price": 0.00585,
"Amount": 0.00007739,
"Total": 4.5e-7
},
{
"Type": "Sell",
"Price": 0.00585,
"Amount": 0.00031039,
"Total": 0.00000181
},
{
"Type": "Buy",
"Price": 8.6e-7,
"Amount": 2070,
"Total": 0.0017802
},
{
"Type": "Buy",
"Price": 0.00187861,
"Amount": 65.81153335,
"Total": 0.1236342
},
{
"Type": "Buy",
"Price": 0.00187858,
"Amount": 15.66747734,
"Total": 0.0294326
},
{
"Type": "Buy",
"Price": 0.00187857,
"Amount": 7.94470487,
"Total": 0.01492468
},
{
"Type": "Buy",
"Price": 0.00187853,
"Amount": 0.78814015,
"Total": 0.00148054
},
{
"Type": "Buy",
"Price": 0.00187852,
"Amount": 0.78814429,
"Total": 0.00148054
},
{
"Type": "Sell",
"Price": 0.00054142,
"Amount": 0.9975,
"Total": 0.00054006
},
{
"Type": "Buy",
"Price": 8.6e-7,
"Amount": 811.9167491,
"Total": 0.00069824
},
{
"Type": "Buy",
"Price": 8.6e-7,
"Amount": 338.0832509,
"Total": 0.00029075
},
{
"Type": "Buy",
"Price": 0.00238719,
"Amount": 72,
"Total": 0.17187768
},
{
"Type": "Buy",
"Price": 0.00236363,
"Amount": 4,
"Total": 0.00945452
},
{
"Type": "Sell",
"Price": 0.00023501,
"Amount": 41.1642077,
"Total": 0.009674
},
{
"Type": "Sell",
"Price": 0.00023501,
"Amount": 2.7697923,
"Total": 0.00065092
},
{
"Type": "Buy",
"Price": 0.00000105,
"Amount": 1270,
"Total": 0.0013335
},
{
"Type": "Buy",
"Price": 0.00281001,
"Amount": 360,
"Total": 1.0116036
},
{
"Type": "Buy",
"Price": 0.00280001,
"Amount": 3.33990832,
"Total": 0.00935177
},
{
"Type": "Sell",
"Price": 0.0038,
"Amount": 208,
"Total": 0.7904
},
{
"Type": "Sell",
"Price": 0.00356245,
"Amount": 1,
"Total": 0.00356245
},
{
"Type": "Sell",
"Price": 0.00370002,
"Amount": 0.02702689,
"Total": 0.0001
},
{
"Type": "Sell",
"Price": 0.00370002,
"Amount": 15.4008193,
"Total": 0.05698333
},
{
"Type": "Sell",
"Price": 0.00370002,
"Amount": 3.09119995,
"Total": 0.0114375
},
{
"Type": "Sell",
"Price": 0.02315202,
"Amount": 6.98549994,
"Total": 0.16172843
},
{
"Type": "Sell",
"Price": 0.02315202,
"Amount": 6e-8,
"Total": 0
},
{
"Type": "Buy",
"Price": 0.00023492,
"Amount": 40,
"Total": 0.0093968
},
{
"Type": "Sell",
"Price": 0.00004456,
"Amount": 40.3006157,
"Total": 0.00179579
},
{
"Type": "Sell",
"Price": 0.00004461,
"Amount": 112.0824927,
"Total": 0.00499999
},
{
"Type": "Sell",
"Price": 0.00004462,
"Amount": 33.61721201,
"Total": 0.00149999
},
{
"Type": "Sell",
"Price": 0.00004463,
"Amount": 33.60967959,
"Total": 0.0015
},
{
"Type": "Buy",
"Price": 0.0002817,
"Amount": 4,
"Total": 0.0011268
},
{
"Type": "Buy",
"Price": 0.00003965,
"Amount": 55.13060038,
"Total": 0.00218592
},
{
"Type": "Buy",
"Price": 0.00003965,
"Amount": 104.8693996,
"Total": 0.00415807
},
{
"Type": "Sell",
"Price": 0.00004129,
"Amount": 149.625,
"Total": 0.00617801
},
{
"Type": "Buy",
"Price": 0.02215591,
"Amount": 3,
"Total": 0.06646773
},
{
"Type": "Buy",
"Price": 0.00004073,
"Amount": 113.3174137,
"Total": 0.00461541
},
{
"Type": "Buy",
"Price": 0.00004072,
"Amount": 36.68258634,
"Total": 0.00149371
},
{
"Type": "Buy",
"Price": 0.0000525,
"Amount": 60,
"Total": 0.00315
},
{
"Type": "Buy",
"Price": 0.01877317,
"Amount": 4,
"Total": 0.07509268
},
{
"Type": "Buy",
"Price": 0.00199501,
"Amount": 43.10755334,
"Total": 0.08599999
},
{
"Type": "Buy",
"Price": 0.00350201,
"Amount": 53.48162609,
"Total": 0.18729318
},
{
"Type": "Buy",
"Price": 0.00350201,
"Amount": 132.1260678,
"Total": 0.46270681
},
{
"Type": "Sell",
"Price": 0.02304826,
"Amount": 17.03647964,
"Total": 0.39266121
},
{
"Type": "Sell",
"Price": 0.02312381,
"Amount": 3.52,
"Total": 0.08139581
},
{
"Type": "Sell",
"Price": 0.02324002,
"Amount": 3.39252036,
"Total": 0.07884224
},
{
"Type": "Buy",
"Price": 0.02459958,
"Amount": 7,
"Total": 0.17219706
},
{
"Type": "Buy",
"Price": 0.01378499,
"Amount": 9,
"Total": 0.12406491
},
{
"Type": "Buy",
"Price": 0.00581178,
"Amount": 1,
"Total": 0.00581178
},
{
"Type": "Buy",
"Price": 0.01498881,
"Amount": 7,
"Total": 0.10492167
},
{
"Type": "Sell",
"Price": 0.00001717,
"Amount": 176.6891735,
"Total": 0.00303375
},
{
"Type": "Sell",
"Price": 0.00001718,
"Amount": 87.31082654,
"Total": 0.00149999
},
{
"Type": "Buy",
"Price": 0.00001464,
"Amount": 182.8870467,
"Total": 0.00267746
},
{
"Type": "Buy",
"Price": 0.00001464,
"Amount": 32.11295335,
"Total": 0.00047013
},
{
"Type": "Buy",
"Price": 0.00596086,
"Amount": 26,
"Total": 0.15498236
},
{
"Type": "Buy",
"Price": 0.000017,
"Amount": 50,
"Total": 0.00085
},
{
"Type": "Buy",
"Price": 0.0005388,
"Amount": 1,
"Total": 0.0005388
},
{
"Type": "Buy",
"Price": 0.00935588,
"Amount": 0.00060288,
"Total": 0.00000564
},
{
"Type": "Buy",
"Price": 0.00935588,
"Amount": 0.99939712,
"Total": 0.00935023
},
{
"Type": "Buy",
"Price": 0.01475001,
"Amount": 1,
"Total": 0.01475001
},
{
"Type": "Buy",
"Price": 0.00555,
"Amount": 21.28693846,
"Total": 0.1181425
},
{
"Type": "Buy",
"Price": 0.00553,
"Amount": 9.26025155,
"Total": 0.05120919
}
]
我展示了如何打印值：
_renderData(){
const data = this.state.sdc
return Object.keys(data).map(function(key,index){
const datum = data[key]
return (<div key={datum.id}>
<p>Type: {datum.Type}</p>
<p>Price: {datum.Price}</p>
<p>Amount: {datum.Amount}</p>
<p>Total: {datum.Total}</p>
</div>)
})
}
现在我试图发挥它，例如：
_extractData() {
const data = this.state.sdc
return Object.keys(data[0])
}
将打印四个标题（类型，价格，金额，总计），但我真的想做一些更复杂的事情。例如。
- 显示一个类型的所有交易：购买
- 显示所有的交易总价值大于x等
我将如何访问所有这些。你能举个例子吗？
编辑：我添加了一个方法如下建议 - 但它不显示任何内容：
import React, {Component} from 'react';
import Header from './header/header';
import Body from './body/body';
import sdc from './data';
export default class App extends Component {
constructor(props) {
super();
// Set the initial grid in
this.state = {
title: "Singularity is nigh!!!",
sdc: sdc
};
}
_renderData(){
const data = this.state.sdc
return Object.keys(data).map(function(key,index){
const datum = data[key]
return (<div key={datum.id}>
<p>Type: {datum.Type}</p>
<p>Price: {datum.Price}</p>
<p>Amount: {datum.Amount}</p>
<p>Total: {datum.Total}</p>
</div>)
})
}
_extractData() {
const data = this.state.sdc
return Object.keys(data[0])
}
_renderBuy() {
const data = this.state.sdc
data.filter(function(element) {
return element.hasOwnProperty("Type") && element.Type == 'Buy';
});
}
render() {
const renderedData = this._renderBuy()
return (
// Add your component markup and other subcomponent references here.
<div>
<Header title={this.state.title} />
{renderedData}
</div>
);
}
}
答
我觉得这更像是一个普通的JavaScript的问题。你所要求的是过滤你的数组中的对象列表，所以通过使用数组的filter方法来达到这个目的。
// Filter all the transactions of type 'Buy'
data.filter(function(element) {
return element.hasOwnProperty("Type") && element.Type == 'Buy';
});
// Filter all the transactions having a total amount greater than or equal to 0.84
data.filter(function(element) {
return element.hasOwnProperty("Total") && element.Total >= 0.84;
});
您从filter得到的输出只是通过测试的元素对象的一个新的数组，所以为了使它们在作出反应，你会需要遍历这个新返回数组，就像你在你的_renderData()实例方法中做过。
我对_renderData方法做了一些细微的修改，以便它接受一个参数，它可以是任何对象数组，因此您不必再次重复相同的代码来渲染“购买”事务，或者任何其他过滤的数组。
_renderData(data){
return Object.keys(data).map(function(key,index){
const datum = data[key]
return (<div key={datum.id}>
<p>Type: {datum.Type}</p>
<p>Price: {datum.Price}</p>
<p>Amount: {datum.Amount}</p>
<p>Total: {datum.Total}</p>
</div>)
})
}
render() {
const renderedData = this._renderData(this._renderBuy());
return (
// Add your component markup and other subcomponent references here.
<div>
<Header title={this.state.title} />
{renderedData}
</div>
);
};
[访问/处理（嵌套的）对象，数组或JSON（的可能的复制http://*.com/questions/11922383/access-process-nested-objects-arrays- or-json） –
这是一个对象数组。 –
所以这与JSON无关，对吧？ – Wasteland