按键组合json数组，javascript
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Combine json arrays by key, javascript
提问by user2083142
I need to combine two json arrays, delivered by two rest services. The entries with the same "id" belong together.
我需要组合两个 json 数组，由两个休息服务提供。具有相同“id”的条目属于一起。
json1 = [{id:1,name:'aaa'},
{id:5,name:'ccc'},
{id:3,name:'bbb'}
];
json2 = [{id:3,parameter1:'x', parameter2:'y', parameter3:'z'},
{id:1,parameter1:'u', parameter2:'v', parameter3:'w'},
{id:5,parameter1:'q', parameter2:'w', parameter3:'e'}
];
I need a combined/copied/cloned json array in javascript in the following way (my model in angular2):
我需要通过以下方式在 javascript 中组合/复制/克隆 json 数组（我的模型在 angular2 中）：
json3 = [{id:3,name:'bbb',parameter1:'x', parameter2:'y', parameter3:'z'},
{id:1,name:'aaa', parameter1:'u', parameter2:'v', parameter3:'w'},
{id:5,name:'ccc', parameter1:'q', parameter2:'w', parameter3:'e'}
];
Is there a way to combine them? The parameter names are not defined exactly and it needs to work with variable parameter vectors.
有没有办法将它们结合起来？参数名称没有准确定义，它需要使用可变参数向量。
I tried it with mixed for each loops. Seems to me very ugly.
我为每个循环尝试了混合。在我看来非常丑陋。
采纳答案by Jacob Petersen
If you wanted to write it so that you could take in any number of arrays, not just 2, you could utilize arguments, and do something like this:
如果您想编写它以便您可以接收任意数量的数组，而不仅仅是 2 个，您可以使用arguments，并执行以下操作：
var json1 = [{id:1,name:'aaa'},{id:5,name:'ccc'},{id:3,name:'bbb'}];
var json2 = [{id:3,parameter1:'x', parameter2:'y', parameter3:'z'},
{id:1,parameter1:'u', parameter2:'v', parameter3:'w'},
{id:5,parameter1:'q', parameter2:'w', parameter3:'e'}
];
function joinObjects() {
var idMap = {};
// Iterate over arguments
for(var i = 0; i < arguments.length; i++) {
// Iterate over individual argument arrays (aka json1, json2)
for(var j = 0; j < arguments[i].length; j++) {
var currentID = arguments[i][j]['id'];
if(!idMap[currentID]) {
idMap[currentID] = {};
}
// Iterate over properties of objects in arrays (aka id, name, etc.)
for(key in arguments[i][j]) {
idMap[currentID][key] = arguments[i][j][key];
}
}
}
// push properties of idMap into an array
var newArray = [];
for(property in idMap) {
newArray.push(idMap[property]);
}
return newArray;
}
var json3 = joinObjects(json1, json2);
回答by georg
Two one-liners:
两个单行：
with lodash:
使用 lodash：
res = _(json1).concat(json2).groupBy('id').map(_.spread(_.assign)).value();
in ES2015:
在 ES2015 中：
res = json2.map(x => Object.assign(x, json1.find(y => y.id == x.id)));
回答by Killian Charlez
ES2015 georg's answer works great;
ES2015 乔治的回答很好；
json1 = [
{id:1, test: 0},
{id:2, test: 0},
{id:3, test: 0},
{id:4, test: 0},
{id:5, test: 0}
];
json2 = [
{id:1, test: 1},
{id:3, test: 1},
{id:5, test: 1}
];
json1.map(x => Object.assign(x, json2.find(y => y.id == x.id)));
result:
结果：
{id:1, test: 1},
{id:2, test: 0},
{id:3, test: 1},
{id:4, test: 0},
{id:5, test: 1}
回答by trincot
Here is a way where you first build an index keyed by id(sparse array) to detect and combine objects with matching idvalues, which then finally are concatenated back into a normal array:
这是一种首先构建以id（稀疏数组）为键的索引的方法，以检测和组合具有匹配id值的对象，然后最终将其连接回普通数组：
json3 = json1.concat(json2).reduce(function(index, obj) {
if (!index[obj.id]) {
index[obj.id] = obj;
} else {
for (prop in obj) {
index[obj.id][prop] = obj[prop];
}
}
return index;
}, []).filter(function(res, obj) {
return obj;
});
json1 = [
{id:1,name:'aaa'},
{id:5,name:'ccc'},
{id:3,name:'bbb'}
];
json2 = [
{id:3,parameter1:'x', parameter2:'y', parameter3:'z'},
{id:1,parameter1:'u', parameter2:'v', parameter3:'w'},
{id:5,parameter1:'q', parameter2:'w', parameter3:'e'}
];
json3 = json1.concat(json2).reduce(function(index, obj) {
if (!index[obj.id]) {
index[obj.id] = obj;
} else {
for (prop in obj) {
index[obj.id][prop] = obj[prop];
}
}
return index;
}, []).filter(function(res, obj) {
return obj;
});
document.write('<pre>', JSON.stringify(json3, null, 4), '</pre>');If your browser supports Object.assign:
如果您的浏览器支持Object.assign：
json3 = json1.concat(json2).reduce(function(index, obj) {
index[obj.id] = Object.assign({}, obj, index[obj.id]);
return index;
}, []).filter(function(res, obj) {
return obj;
});
回答by Barmar
Use nested loops to find the corresponding elements and merge them.
使用嵌套循环查找相应的元素并合并它们。
for (var i = 0; i < json1.length; i++) {
var id = json1[i].id;
for (var j = 0; j < json2.length; j++) {
if (json2[j].id == id) {
for (var key in json2[j]) {
json1[i][key] = json2[j][key];
}
break;
}
}
}
At the end, json1will contain the combined elements.
最后，json1将包含组合元素。
The above code assumes that every element of json2matches something in json1. If there can be extra elements in json2, you'll need an additional loop afterward to copy those over to json1.
上面的代码假设 的每个元素都json2匹配json1. 如果 中可以有额外的元素json2，之后您将需要一个额外的循环来将这些元素复制到json1.
回答by KARTHIKEYAN.A
Use forEachand filterwe can resolve the requirement.
使用forEach和filter我们可以解决需求。
vehicleArray1 = [{id:1, name: "a"},{id:2, name: "b"},{id:3, name:"c"}];
vehicleArray2 = [{id:1, type: "two wheeler"},{id:2, type: "four wheeler"},{id:3, type:"six wheeler"}];
var outArr = [];
vehicleArray1.forEach(function(value) {
var existing = vehicleArray2.filter(function(v, i) {
return (v.id == value.id);
});
if (existing.length) {
value.type = existing[0].type;
outArr.push(value)
} else {
value.type = '';
outArr.push(value);
}
});
console.log(outArr)回答by PrisonPants
let json1 = [
{id:1,name:'aaa'},
{id:5,name:'ccc'},
{id:3,name:'bbb'}
];
let json2 = [
{id:3,parameter1:'x', parameter2:'y', parameter3:'z'},
{id:1,parameter1:'u', parameter2:'v', parameter3:'w'},
{id:5,parameter1:'q', parameter2:'w', parameter3:'e'}
];
let result = json1.map(obj => {
let data = json2.find(item => item.id === obj.id);
return {...obj, ...data}
});
回答by Luke
This should do it for you. I hope the code makes sense on its own. This example will always take the json1value over the json2value if both exist. If you want to change that then you need to switch the object references (src[i]and obj[j]) in the innermost loop.
这应该为你做。我希望代码本身有意义。如果两者都存在，则此示例将始终采用json1值代替json2值。如果你想改变它，那么你需要在最内层循环中切换对象引用（src[i]和obj[j]）。
// Will take src, and merge in the contents of obj.
// Expects an array of objects for both.
// Will keep src values in favour of obj values.
function extend(src, obj) {
// Loop the src, in this case json1
for (var i = 0; i < src.length; i++) {
// For every loop of json1, also loop json2
for (var j = 0; j < obj.length; j++) {
// If we have matching IDs operate on this pair
if (src[i].id == obj[j].id) {
// For every key in the object being merged in,
// if the key exists in src, ignore new value.
// if the doesn't exist in src, take the new value.
for (var key in obj[j]) {
src[i][key] = src[i].hasOwnProperty(key) ? src[i][key] : obj[j][key];
}
// We found our matching pair, so break out of the json2 loop
break;
}
}
}
return src;
}
// -------------------------------------------
var json1 = [{
id: 1,
name: 'aaa'
},{
id: 5,
name: 'ccc'
},{
id: 3,
name: 'bbb'
}];
var json2 = [{
id: 3,
parameter1: 'x',
parameter2: 'y',
parameter3: 'z'
},{
id: 1,
parameter1: 'u',
parameter2: 'v',
parameter3: 'w'
},{
id: 5,
parameter1: 'q',
parameter2: 'w',
parameter3: 'e'
}];
var json3 = extend(json1, json2);
// ---------------------------------------------
var pre = document.getElementById('out');
pre.innerHTML = JSON.stringify(json3);<pre id="out"></pre>