Exploring the process of iterating through and organizing a JavaScript array

Question

Exploring the process of iterating through and organizing a JavaScript array

Recently, I encountered a JavaScript object that was generated by a particular API. The object is structured in a way that it can potentially have multiple instances of the same 'equity' (such as Hitachi Home in this case):

  {
    "results": {
      "holdings": [{
        "equity": {
          "text": "Hitachi Home"
        },
        "holding_pc": "6.48",
        "sector": "Consumer Durables",
        "shares_no": "1537.00",
        "value_cr": "0.24"
      }, {
        "equity": {
          "text": "Mahindra CIE"
        },
        "holding_pc": "6.34",
        "sector": "Manufacturing",
        "shares_no": "10376.00",
        "value_cr": "0.24"
      }, {
        "equity": {
          "text": "Schneider Infra"
        },
        "holding_pc": "5.33",
        "sector": "Utilities",
        "shares_no": "9518.00",
        "value_cr": "0.20",
      }, {
        "equity": {
          "text": "Hitachi Home"
        },
        "holding_pc": "2.18",
        "sector": "Consumer Durables",
        "shares_no": "437.00",
        "value_cr": "0.12"
      }]
    }
  }

I am currently exploring the best approach to develop a JavaScript function that can take this entire object as input, iterate through all the records, and consolidate the data so that records with the same 'equity' are summed and merged. For example, the equity 'Hitachi Home' should be consolidated as follows:

  {
    "results": {
      "holdings": [{
        "equity": {
          "text": "Hitachi Home"
        },
        "holding_pc": "8.66",
        "sector": "Consumer Durables",
        "shares_no": "1974.00",
        "value_cr": "0.36"
      }, {
        "equity": {
          "text": "Mahindra CIE"
        },
        "holding_pc": "6.34",
        "sector": "Manufacturing",
        "shares_no": "10376.00",
        "value_cr": "0.24"
      }, {
        "equity": {
          "text": "Schneider Infra"
        },
        "holding_pc": "5.33",
        "sector": "Utilities",
        "shares_no": "9518.00",
        "value_cr": "0.20",
      }]
    }
  }

My objective is to create a JS function that can aggregate all equities with the same text. Below is a high-level overview of the function I am working on:

function transform(data) {
  function sumHoldings(row) {
    newrow = {};
    newrow.equity = row.equity.text;
    newrow.holding_pc = row.holding_pc;
    return newrow;
  }
  for(var holdings in data.results) {
    data.results.total_holdings = data.results.holdings.map(sumHoldings);
  };

  return data;
}

javascript json object

Answer 1

Answer №1

You can condense the initial array in the following manner:

var data = {
  "data": {
    "items": [{
      "name": {
        "text": "Apple"
      },
      "quantity": "10",
      "category": "Fruits",
      "price": "2.50"
    }, {
      "name": {
        "text": "Carrot"
      },
      "quantity": "15",
      "category": "Vegetables",
      "price": "1.20"
    }, {
      "name": {
        "text": "Banana"
      },
      "quantity": "20",
      "category": "Fruits",
      "price": "0.80"
    }, {
      "name": {
        "text": "Carrot"
      },
      "quantity": "5",
      "category": "Vegetables",
      "price": "0.60"
    }]
  }
}

function findFirstElement(elements, condition) {
  for (var i = 0; i < elements.length; i++) {
    if (condition(elements[i])) {
      return elements[i];
    }
  }
  return null;
}

var condensedResult = data.data.items.reduce(function (arr, item) {
  item.quantity = Number(item.quantity);
  item.price = Number(item.price);
  var element = findFirstElement(arr, function (_item) { return _item.name.text === item.name.text });
  if (element) {
    // If element is found, perform calculations
    element.quantity += item.quantity;
    element.price += item.price;
  } else {
    // If element is not found, add to the array
    arr.push(item);
  }
  return arr;
}, []);


document.querySelector('#output').innerHTML = JSON.stringify({ data: { items: condensedResult } }, undefined, 4);

<pre id="output"></pre>

Answer 2

You can condense the initial array in the following manner:

var data = {
  "data": {
    "items": [{
      "name": {
        "text": "Apple"
      },
      "quantity": "10",
      "category": "Fruits",
      "price": "2.50"
    }, {
      "name": {
        "text": "Carrot"
      },
      "quantity": "15",
      "category": "Vegetables",
      "price": "1.20"
    }, {
      "name": {
        "text": "Banana"
      },
      "quantity": "20",
      "category": "Fruits",
      "price": "0.80"
    }, {
      "name": {
        "text": "Carrot"
      },
      "quantity": "5",
      "category": "Vegetables",
      "price": "0.60"
    }]
  }
}

function findFirstElement(elements, condition) {
  for (var i = 0; i < elements.length; i++) {
    if (condition(elements[i])) {
      return elements[i];
    }
  }
  return null;
}

var condensedResult = data.data.items.reduce(function (arr, item) {
  item.quantity = Number(item.quantity);
  item.price = Number(item.price);
  var element = findFirstElement(arr, function (_item) { return _item.name.text === item.name.text });
  if (element) {
    // If element is found, perform calculations
    element.quantity += item.quantity;
    element.price += item.price;
  } else {
    // If element is not found, add to the array
    arr.push(item);
  }
  return arr;
}, []);


document.querySelector('#output').innerHTML = JSON.stringify({ data: { items: condensedResult } }, undefined, 4);

<pre id="output"></pre>

Answer 3

Answer №2

To streamline your data management process, I recommend creating a holdings object that can consolidate all the necessary information and be easily accessed using unique holdings names.

One way to achieve this is by iterating through your holdings array and transferring the data from the original object to a new consolidatedHoldings object. Here's a general outline of how you can do this:

var consolidatedHoldings = {};

obj.results.holdings.forEach(function(holding){
    holding.forEach(function (holdingDataValue, holdingDataIndex) {
        if (!isNaN(parseFloat(holdingDataValue)) && isFinite(holdingDataValue)) {
            consolidatedHoldings[holdingDataIndex] = consolidatedHoldings[holdingDataIndex] + parseFloat(holdingDataValue);
        } else {
            consolidatedHoldings[holdingDataValue] = holdingDataValue;
        }
    });
});

By following this approach, you can ensure that the consolidated holdings object is accurately updated. Any new keys will be created if they don't already exist, and existing keys will be overwritten with the updated data. Additionally, numerical values will be added together.

Once you have the consolidated holdings object, you may consider converting it into an array and integrating it back into your original object for easier data management.

Answer 4

To streamline your data management process, I recommend creating a holdings object that can consolidate all the necessary information and be easily accessed using unique holdings names.

One way to achieve this is by iterating through your holdings array and transferring the data from the original object to a new consolidatedHoldings object. Here's a general outline of how you can do this:

var consolidatedHoldings = {};

obj.results.holdings.forEach(function(holding){
    holding.forEach(function (holdingDataValue, holdingDataIndex) {
        if (!isNaN(parseFloat(holdingDataValue)) && isFinite(holdingDataValue)) {
            consolidatedHoldings[holdingDataIndex] = consolidatedHoldings[holdingDataIndex] + parseFloat(holdingDataValue);
        } else {
            consolidatedHoldings[holdingDataValue] = holdingDataValue;
        }
    });
});

By following this approach, you can ensure that the consolidated holdings object is accurately updated. Any new keys will be created if they don't already exist, and existing keys will be overwritten with the updated data. Additionally, numerical values will be added together.

Once you have the consolidated holdings object, you may consider converting it into an array and integrating it back into your original object for easier data management.

Answer 5

Answer №3

let holdingsMap = {};

a.holdings.forEach(function(holding){  
   let text = holding.equity.text;
   let entry = holdingsMap[text] || (holdingsMap[text] = []);

   entry.push(holding);
});

Object.keys(holdingsMap).map(function(key) {
  let values = holdingsMap[key];
  let parseFloats = function(a, b) { return parseFloat(a) + parseFloat(b); };

  return {
     equity: {
        "text" : key
     },
     sector : values[0].sector,
     value_cr: values.map(function(e) { return e.value_cr; }).reduce(parseFloats, 0), 
     shares_no: values.map(function(e) { return e.shares_no; }).reduce(parseFloats, 0), 
     holding_pc : values.map(function(e) { return e.holding_pc; }).reduce(parseFloats, 0)
   }
});

Answer 6

let holdingsMap = {};

a.holdings.forEach(function(holding){  
   let text = holding.equity.text;
   let entry = holdingsMap[text] || (holdingsMap[text] = []);

   entry.push(holding);
});

Object.keys(holdingsMap).map(function(key) {
  let values = holdingsMap[key];
  let parseFloats = function(a, b) { return parseFloat(a) + parseFloat(b); };

  return {
     equity: {
        "text" : key
     },
     sector : values[0].sector,
     value_cr: values.map(function(e) { return e.value_cr; }).reduce(parseFloats, 0), 
     shares_no: values.map(function(e) { return e.shares_no; }).reduce(parseFloats, 0), 
     holding_pc : values.map(function(e) { return e.holding_pc; }).reduce(parseFloats, 0)
   }
});

Answer 7

Answer №4

To optimize your code, make sure to iterate through the arrays instead of the objects. This will allow you to efficiently access the properties of the object. Consider the following approach:

obj.results.holdings.forEach(function(holding){
    // Access the equity string using holding.equity.text
    // Handle uniqueness as needed, such as by adding it to an array only if it's not already included
});

Upon further review, it seems that your goal is to reduce the array, not just find unique elements. You can achieve this by:

var equity = { };
var sums = ['holding_pc', 'shares_no', 'value_cr'];
var holdings = obj.results.holdings.reduce(function(previousValue, currentValue){
    var currentEquity = currentValue.equity.text;
    if(equity[currentEquity] !== undefined){
        // Update existing equity values in the reduced array
        oldObj = previousValue[equity[currentEquity]];
        sums.forEach(function(prop){
           oldObj[prop] = Number(oldObj[prop]) + Number(currentValue[prop]); 
        });
    } else {
        // Add new equity values to the reduced array
        equity[currentEquity] = previousValue.length;
        previousValue.push(currentValue);
    }
    return previousValue;
}, []);
// The holdings variable now contains the reduced array of objects

Answer 8

To optimize your code, make sure to iterate through the arrays instead of the objects. This will allow you to efficiently access the properties of the object. Consider the following approach:

obj.results.holdings.forEach(function(holding){
    // Access the equity string using holding.equity.text
    // Handle uniqueness as needed, such as by adding it to an array only if it's not already included
});

Upon further review, it seems that your goal is to reduce the array, not just find unique elements. You can achieve this by:

var equity = { };
var sums = ['holding_pc', 'shares_no', 'value_cr'];
var holdings = obj.results.holdings.reduce(function(previousValue, currentValue){
    var currentEquity = currentValue.equity.text;
    if(equity[currentEquity] !== undefined){
        // Update existing equity values in the reduced array
        oldObj = previousValue[equity[currentEquity]];
        sums.forEach(function(prop){
           oldObj[prop] = Number(oldObj[prop]) + Number(currentValue[prop]); 
        });
    } else {
        // Add new equity values to the reduced array
        equity[currentEquity] = previousValue.length;
        previousValue.push(currentValue);
    }
    return previousValue;
}, []);
// The holdings variable now contains the reduced array of objects

Exploring the process of iterating through and organizing a JavaScript array

Answer №1

Answer №2

Answer №3

Answer №4

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