如何从javascript中的现有数组创建一个新数组

Question

I am a newbie in Javascript, I have to filter an array so I have googled, and spent my time to find the solution but no one helped me.PLZ help me. I have the following array which is the result of a query:

"clause": [
    {
        "clause_id": 1,
        "clause_text": "A",
        "clause_item_id": 1,
        "item_text": "this text is related to clause 1 ",
        "item_photo": ""
    },
    {
        "clause_id": 2,
        "clause_text": "B",
        "clause_item_id": 2,
        "item_text": "this text is related to clause 2 ",
        "item_photo": ""
    },
    {
        "clause_id": 2,
        "clause_text": "B",
        "clause_item_id": 3,
        "item_text": "this text is related to clause 2",
        "item_photo": ""
    },
    {
        "clause_id": 2,
        "clause_text": "B",
        "clause_item_id": 4,
        "item_text": "this text is related to clause 2",
        "item_photo": ""
    },
    {
        "clause_id": 3,
        "clause_text": "C",
        "clause_item_id": 5,
        "item_text": "this text is related to clause 3",
        "item_photo": ""
    },
    {
        "clause_id": 3,
        "clause_text": "C",
        "clause_item_id": 6,
        "item_text": "this text is related to clause 3",
        "item_photo": ""
    },
    {
        "clause_id": 3,
        "clause_text": "C",
        "clause_item_id": 7,
        "item_text": "this text is related to clause 3",
        "item_photo": ""
    }
]

I want to change it's format. and send it as JSON response to the client. so the above array should be filtered by clause id which is repeated many times. I want to reformat the array and avoid from the repetition of some array elements. so the final array which I want is this:

    {    "clauses": [
    {
        "cls": {
            "clause_id": 1,
            "clause_text": "A"
        },
        "items": [
            {
                "claud_item_id": 1,
                "item_text": "this text is related to clause 1",
                "item_photo": ""
            }
        ]
    },
    {
        "cls": {
            "clause_id": 2,
            "clause_text": "B"
        },
        "items": [
            {
                "claud_item_id": 2,
                "item_text": "this text is related to clause 2",
                "item_photo": ""
            },
            {
                "claud_item_id": 3,
                "item_text": "this text is related to clause 2",
                "item_photo": ""
            },
            {
                "claud_item_id": 4,
                "item_text": "this text is related to clause 2",
                "item_photo": ""
            }
        ]
    },
    {
        "cls": {
            "clause_id": 3,
            "clause_text": "C"
        },
        "items": [
            {
                "claud_item_id": 5,
                "item_text": "this text is related to clause 3",
                "item_photo": ""
            },
            {
                "claud_item_id": 6,
                "item_text": "this text is related to clause 3",
                "item_photo": ""
            },
            {
                "claud_item_id": 7,
                "item_text": "this text is related to clause 3",
                "item_photo": ""
            }
        ]
    }
]

}

PLZ help me

Answer 1

 var item_val = item_val = {"clause": [ { "clause_id": 1, "clause_text": "A", "clause_item_id": 1, "item_text": "this text is related to clause 1 ", "item_photo": "" }, { "clause_id": 2, "clause_text": "B", "clause_item_id": 2, "item_text": "this text is related to clause 2 ", "item_photo": "" }, { "clause_id": 2, "clause_text": "B", "clause_item_id": 3, "item_text": "this text is related to clause 2", "item_photo": "" }, { "clause_id": 2, "clause_text": "B", "clause_item_id": 4, "item_text": "this text is related to clause 2", "item_photo": "" }, { "clause_id": 3, "clause_text": "C", "clause_item_id": 5, "item_text": "this text is related to clause 3", "item_photo": "" }, { "clause_id": 3, "clause_text": "C", "clause_item_id": 6, "item_text": "this text is related to clause 3", "item_photo": "" }, { "clause_id": 3, "clause_text": "C", "clause_item_id": 7, "item_text": "this text is related to clause 3", "item_photo": "" } ] } var result_val = {}; item_val['clause'].forEach(function(val){ var t = {'item_photo': val['item_photo'],'item_text':val['item_text'],'clause_item_id':val['clause_item_id']} if(!(val['clause_id'] in result_val)) result_val[val['clause_id']] = {} if(!(val['clause_text'] in result_val[val['clause_id']])) result_val[val['clause_id']][val['clause_text']] = {} if('item' in result_val[val['clause_id']][val['clause_text']]){ result_val[val['clause_id']][val['clause_text']]['item'].push(t) }else{ result_val[val['clause_id']][val['clause_text']]['item'] = [] result_val[val['clause_id']][val['clause_text']]['item'].push(t) } }) console.log(result_val)

Answer 2

So you can build out a new javascript object, but it might be tricky if you have object attributes of 'items' repeated over in the same object. I fixed this by making the results have an array of items like so.

The algorithm is using a double for loop so it would be expensive for large json sizes, but it works.

Here's the code and output assuming the json object to be sorted is named 'obj'.

var newObj = {"clause":[]};
var i,j;
for(i = 0; i < obj.clause.length; i++){
  var current = obj.clause[i];
  for(j = 0; j < newObj.clause.length; j++){
    if(newObj.clause[j].cls && newObj.clause[j].cls["clause_id"] == current["clause_id"]){
      var subObj = {"claud_item_id": current["clause_item_id"], "item_text": current["item_text"], "item_photo": current["item_photo"]};    
      newObj.clause[j].items.push(subObj);
      break;
    }
  }
  if(j == newObj.clause.length){
    var subObj = {"cls": {"clause_id": current["clause_id"], "clause_text": current["clause_text"]}, 
                  "items": [{"claud_item_id": current["clause_item_id"], "item_text": current["item_text"], "item_photo": current["item_photo"]}]};     
    newObj.clause.push(subObj);
  }
}

Here's the value of newObj.

{
"clause": [{
    "cls": {
        "clause_id": 1,
        "clause_text": "A"
    },
    "items": [{
        "claud_item_id": 1,
        "item_text": "this text is related to clause 1 ",
        "item_photo": ""
    }]
}, {
    "cls": {
        "clause_id": 2,
        "clause_text": "B"
    },
    "items": [{
        "claud_item_id": 2,
        "item_text": "this text is related to clause 2 ",
        "item_photo": ""
    }, {
        "claud_item_id": 3,
        "item_text": "this text is related to clause 2",
        "item_photo": ""
    }, {
        "claud_item_id": 4,
        "item_text": "this text is related to clause 2",
        "item_photo": ""
    }]
}, {
    "cls": {
        "clause_id": 3,
        "clause_text": "C"
    },
    "items": [{
        "claud_item_id": 5,
        "item_text": "this text is related to clause 3",
        "item_photo": ""
    }, {
        "claud_item_id": 6,
        "item_text": "this text is related to clause 3",
        "item_photo": ""
    }, {
        "claud_item_id": 7,
        "item_text": "this text is related to clause 3",
        "item_photo": ""
    }]
}]
}