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Combine json arrays by key, javascript

I need to combine two json arrays, delivered by two rest services. The entries with the same “id” belong together.

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):

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.

I tried it with mixed for each loops. Seems to me very ugly.

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Answer

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:

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);

console.log(JSON.stringify(json3));
.as-console-wrapper { max-height: 100% !important; top: 0; }

Here is a working codepen.

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