Javascript get value in json based on another value - Stack Overflow

admin 管理员组

文章数量: 1086019

I have a json similar to this one

 {      
    "id": "1",
    "month": "January",
    "type": "inc",
    "Value": "780.00",
    "year": "2018",
  },

 {      
    "id": "2",
    "month": "January",
    "type": "inc",
    "Value": "80.00",
    "year": "2018",
  },
 {      
    "id": "3",
    "month": "February",
    "type": "inc",
    "Value": "100.00",
    "year": "2018",
  },...

Now I need to get all the Value from the object for all the months, as you can see I may have more objects with the same month name. The closer I got to was creating 2 arrays 1 with the list of Months and 1 with the value but I got stuck, can someone lead me to the correct path?

The desired output would be to get an array like that ["January"=>1500, "February"=>2000...] or have 2 arrays, 1 with the list of months where there is ine (I already have it) and the second the total ine for these months, so it's like this: ["January", "February", "March"..] and the second one [1500, 2000, 300...]

I have a json similar to this one

 {      
    "id": "1",
    "month": "January",
    "type": "inc",
    "Value": "780.00",
    "year": "2018",
  },

 {      
    "id": "2",
    "month": "January",
    "type": "inc",
    "Value": "80.00",
    "year": "2018",
  },
 {      
    "id": "3",
    "month": "February",
    "type": "inc",
    "Value": "100.00",
    "year": "2018",
  },...

Now I need to get all the Value from the object for all the months, as you can see I may have more objects with the same month name. The closer I got to was creating 2 arrays 1 with the list of Months and 1 with the value but I got stuck, can someone lead me to the correct path?

The desired output would be to get an array like that ["January"=>1500, "February"=>2000...] or have 2 arrays, 1 with the list of months where there is ine (I already have it) and the second the total ine for these months, so it's like this: ["January", "February", "March"..] and the second one [1500, 2000, 300...]

• javascript
• json

Share Improve this question Follow edited Nov 2, 2018 at 14:50 loliki asked Nov 2, 2018 at 14:42 lolikiloliki 95722 gold badges1616 silver badges3939 bronze badges 1

• 3 Post the desired output and what you've tried so far. – Ele Commented Nov 2, 2018 at 14:44

Add a ment  | 

6 Answers 6

Sorted by: Reset to default 5

You can use the function Array.prototype.reduce to sum each Value by month.

let arr =  [{          "id": "1",    "month": "January",    "type": "inc",    "Value": "780.00",    "year": "2018",  }, {          "id": "2",    "month": "January",    "type": "inc",    "Value": "80.00",    "year": "2018",  }, {          "id": "3",    "month": "February",    "type": "inc",    "Value": "100.00",    "year": "2018",  }],
    result = arr.reduce((a, {month, Value}) => {
      a[month] = (a[month] || 0) + +Value;
      return a;
    }, Object.create(null));
  
console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

I actually can barely understand what you would like to achieve. Please provide some example. If I understood you correctly, you can use map function of js array to map each object to its Value.

let arr = [...];
console.log(arr.map(item => item.Value));

You can do

    var fabuaryDate = yourdata
.filter(function(data) { return data.month == "February" })
.map(function(x){return {value: x.Value} })

To get result in following format :

{
  jan : [1,2,3],
  feb : [3,4,5,6],
  april : [3,4,5]
}

do this :

var output = {}
arr.forEach(element => {
   if(!output[element.month]){
      output[month] = new Array();
   }
   output[month].push(element.value);
});

You can iterate the object and fill an array with the values of the field you want to extract, like so:

const data = [ {      
    "id": "1",
    "month": "January",
    "type": "inc",
    "Value": 780.00,
    "year": "2018",
  },
  {      
    "id": "2",
    "month": "January",
    "type": "inc",
    "Value": 80.00,
    "year": "2018",
  },
  {      
    "id": "3",
    "month": "February",
    "type": "inc",
    "Value": 100.00,
    "year": "2018",
  }];
  
let dataArray = data.reduce((accum, d) => {
  if(!accum[d.month]) accum[d.month] = 0;
  accum[d.month] += d.Value;
  return accum;
},{});
console.log(dataArray);

Although you don't seem to be clear enough with what have you tried here is an example of what you could do in order to read all the values inside the json.

function myFunction(item) {
   console.log(item.month + " with the value " + item.Value)
}

var jsonArray = [{"id": "1","month": "January", "type": "inc", "Value": "780.00", "year": "2018" }, { "id": "2",      "month": "January",  "type": "inc",   "Value": "80.00", "year": "2018"  }, { "id": "3", "month": "February",      "type": "inc", "Value": "100.00", "year": "2018" }];

jsonArray.forEach(myFunction);

Since you're working with an array of objects you must access to each of the objects in the array and then get the attribute that you require.

Hope this help, have a great day.

本文标签： Javascript get value in json based on another valueStack Overflow