Using a conditional statement in a JavaScript loop

Question

Using a conditional statement in a JavaScript loop

Here is the data I have:

    companyList: [
      {
        company_name: 'company1',
        item: 'item1'
      },
      {
        company_name: 'company1',
        item: 'item2'
      },
      {
        company_name: 'company1',
        item: 'item3'
      },
      {
        company_name: 'company2',
        item: 'item4'
      }
    ]

This is the desired output format:

    result: [
      {
        company_name: 'company1',
        product: [
          { item: 'item1'},
          { item: 'item2'},
          { item: 'item3'}
        ]
      },
      {
        company_name: 'company2',
        product: [
          { item: 'item4'}
        ]
      }
    ]

How can I achieve this output using map?

javascript arrays loops duplicates

Answer 1

Answer №1

To achieve the desired output efficiently, you can iterate through the array of companyList with a time complexity of O(n). Here's a sample code snippet to demonstrate this:

var companyList = [{
  company_name: 'company1',
  item: 'item1'
}, {
  company_name: 'company1',
  item: 'item2'
}, {
  company_name: 'company1',
  item: 'item3'
}, {
  company_name: 'company2',
  item: 'item4'
}];

var tempObj = {};
companyList.forEach((companyObj) => {
  if(tempObj[companyObj.company_name]){
    tempObj[companyObj.company_name].product.push({item: companyObj.item});
  } else {
    tempObj[companyObj.company_name] = {
      company_name: companyObj.company_name,
      product: [{item: companyObj.item}]
    }
  }
});
var result = Object.values(tempObj);
console.log(result);

Answer 2

To achieve the desired output efficiently, you can iterate through the array of companyList with a time complexity of O(n). Here's a sample code snippet to demonstrate this:

var companyList = [{
  company_name: 'company1',
  item: 'item1'
}, {
  company_name: 'company1',
  item: 'item2'
}, {
  company_name: 'company1',
  item: 'item3'
}, {
  company_name: 'company2',
  item: 'item4'
}];

var tempObj = {};
companyList.forEach((companyObj) => {
  if(tempObj[companyObj.company_name]){
    tempObj[companyObj.company_name].product.push({item: companyObj.item});
  } else {
    tempObj[companyObj.company_name] = {
      company_name: companyObj.company_name,
      product: [{item: companyObj.item}]
    }
  }
});
var result = Object.values(tempObj);
console.log(result);

Answer 3

Answer №2

You have the ability to utilize the reduce method in order to generate a new array

let companyList = [{
    company_name: 'company1',
    item: 'item1'
  },
  {
    company_name: 'company1',
    item: 'item2'
  },
  {
    company_name: 'company1',
    item: 'item3'
  },
  {
    company_name: 'company2',
    item: 'item4'
  }
]

let result = companyList.reduce(function(acc, curr) {
  // Implement findIndex to locate the index of the object with matching company_name
  let findIndex = acc.findIndex(function(item) {
    return item.company_name === curr.company_name;
  });
  // If company_name does not exist, -1 will be returned
  if (findIndex === -1) {
    let obj = {};
    // Create a new object and push the value into it
    obj.company_name = curr.company_name;
    obj.product = [{
      item: curr.item
    }];
    acc.push(obj)
  } else {
    // If the company_name exists, update the product list
    acc[findIndex].product.push({
      item: curr.item
    })
  }
  return acc;
}, []);
console.log(result)

Answer 4

You have the ability to utilize the reduce method in order to generate a new array

let companyList = [{
    company_name: 'company1',
    item: 'item1'
  },
  {
    company_name: 'company1',
    item: 'item2'
  },
  {
    company_name: 'company1',
    item: 'item3'
  },
  {
    company_name: 'company2',
    item: 'item4'
  }
]

let result = companyList.reduce(function(acc, curr) {
  // Implement findIndex to locate the index of the object with matching company_name
  let findIndex = acc.findIndex(function(item) {
    return item.company_name === curr.company_name;
  });
  // If company_name does not exist, -1 will be returned
  if (findIndex === -1) {
    let obj = {};
    // Create a new object and push the value into it
    obj.company_name = curr.company_name;
    obj.product = [{
      item: curr.item
    }];
    acc.push(obj)
  } else {
    // If the company_name exists, update the product list
    acc[findIndex].product.push({
      item: curr.item
    })
  }
  return acc;
}, []);
console.log(result)

Using a conditional statement in a JavaScript loop

Answer №1

Answer №2

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