从2个HTTP请求的元素创建新数组

Question

I have 2 json arrays which are the results of 2 http.get requests. One contains a watch list like:

json1= [
{“id”:6,”ticker”:”PG”,”gt_lt”:”<“,”price_trigger”:75},
{“id”:8,”ticker”:”T”,”gt_lt”:”<“,”price_trigger”:39.5},
{“id”:9,”ticker”:”WM”,”gt_lt”:”<“,”price_trigger”:60}
];

The second one contains stock pricing info:

json2 = [
{“symbol”:”PG”,”name”:”Procter & Gamble Company (The) “,”lastTradeDate”:null,”lastTradePriceOnly”:88.4,”change”:0.35,”dividendYield”:3.04,”peRatio”:23.93,”volume”:1333524},
{“symbol”:”T”,”name”:”AT&T Inc.”,”lastTradeDate”:null,”lastTradePriceOnly”:39.94,”change”:-0.26,”dividendYield”:4.78,”peRatio”:17.22,”volume”:2865061},
{“symbol”:”WM”,”name”:”Waste Management, Inc. Common S”,”lastTradeDate”:null,”lastTradePriceOnly”:62.98,”change”:0.17,”dividendYield”:2.61,”peRatio”:24.61,”volume”:276554}
];

I wish to create a third json array or object comprised of the first array and all elements of second array where "ticker"(json1) == "symbol"(json2). This would allow me to utilize ngFor on the new array and get all the required info into one list or table. Any help would be greatly appreciated.

Answer 1

Here is a way to do what you want:

let json3 = json1.map(item1 => [item1, json2.find(item2 => item2.symbol === item1.ticker)])

The result is an array consisting of subarrays of two elements: item json1 and associated item of json2 .

---

EDIT A find polyfill:

Here is a polyfill for the find method that I grabbed from MDN :

if (!Array.prototype.find) {
  Object.defineProperty(Array.prototype, 'find', {
    value: function(predicate) {
     'use strict';
     if (this == null) {
       throw new TypeError('Array.prototype.find called on null or undefined');
     }
     if (typeof predicate !== 'function') {
       throw new TypeError('predicate must be a function');
     }
     var list = Object(this);
     var length = list.length >>> 0;
     var thisArg = arguments[1];
     var value;

     for (var i = 0; i < length; i++) {
       value = list[i];
       if (predicate.call(thisArg, value, i, list)) {
         return value;
       }
     }
     return undefined;
    }
  });
}

Place this somewhere at the start of your program. It can go in a script file loaded by the browser early on.

Answer 2

You can do it like this, easy way:

var json3 = [];

json1.forEach(function(v,i){
    json2.forEach(function(b,j){
        if(b.symbol == v.ticker)
            json3.push(Object.assign({},v,b));
    });
});