Navigating through Javascript Arrays with Conditions to Separate Objects

Question

Navigating through Javascript Arrays with Conditions to Separate Objects

If we consider a variable called data, can we extract specific items from an array based on the totalaccount value? For instance, before the first occurrence of totalaccount, there are three accounts that I want to retrieve.

Similarly, before the final totalaccount excluding the initial one, there are two accounts for which I need information extraction. How can we transform the array into the desired format below?

let firstOne = {loanname: "Mr X", acnumber: "020000000000001", outstanding: "54000"},
    {loanname: "Mrs Y", acnumber: "020000000000087", outstanding: "87000"},
    {loanname: "Mr Z", acnumber: "020000000000103", outstanding: "15000"},

let secondOne ={loanname: "David", acnumber: "020000000000091", outstanding: "11000"},
    {loanname: "James", acnumber: "020000000001291", outstanding: "4000"},

javascript arrays object

Answer 1

Answer №1

To accomplish this task, utilize the reduce function.

Start by checking for the presence of the totalaccount property. If it exists, create a new array within the accumulator (acc) using the push method of Array.prototype. If the totalaccount property does not exist, simply push the object into the last array of acc. Keep track of the index of the last array element with current

const data = [
  { loanname: "Mr X", acnumber: "020000000000001", outstanding: "54000" },
  { loanname: "Mrs Y", acnumber: "020000000000087", outstanding: "87000" },
  { loanname: "Mr Z", acnumber: "020000000000103", outstanding: "15000" },
  { totalaccount: "3", outstanding: "156000" },
  { loanname: "David", acnumber: "020000000000091", outstanding: "11000" },
  { loanname: "James", acnumber: "020000000001291", outstanding: "4000" },
  { totalaccount: "2", outstanding: "15000" },
];

let current = 0;
const result = data.reduce((acc, curr) => {
    const { totalaccount } = curr;
    if (totalaccount) {
      acc.push([]);
      ++current;
    } else {
      acc[current].push(curr);
    }
    return acc;
  },
  [[]]
);

const [first, second] = result;
console.log(first);
console.log(second);
console.log(result);

You can achieve the same outcome without explicitly tracking the current index as shown below:

const data = [
  { loanname: "Mr X", acnumber: "020000000000001", outstanding: "54000" },
  { loanname: "Mrs Y", acnumber: "020000000000087", outstanding: "87000" },
  { loanname: "Mr Z", acnumber: "020000000000103", outstanding: "15000" },
  { totalaccount: "3", outstanding: "156000" },
  { loanname: "David", acnumber: "020000000000091", outstanding: "11000" },
  { loanname: "James", acnumber: "020000000001291", outstanding: "4000" },
  { totalaccount: "2", outstanding: "15000" },
];

const result = data.reduce(
  (acc, curr) => {
    const { totalaccount } = curr;
    if (totalaccount) {
      acc.push([]);
    } else {
      acc[acc.length - 1].push(curr);
    }
    return acc;
  },
  [[]]
);

console.log(result);

If you wish to aggregate into a single object and dynamically create properties

const data = [
  { loanname: "Mr X", acnumber: "020000000000001", outstanding: "54000" },
  { loanname: "Mrs Y", acnumber: "020000000000087", outstanding: "87000" },
  { loanname: "Mr Z", acnumber: "020000000000103", outstanding: "15000" },
  { totalaccount: "3", outstanding: "156000" },
  { loanname: "David", acnumber: "020000000000091", outstanding: "11000" },
  { loanname: "James", acnumber: "020000000001291", outstanding: "4000" },
  { totalaccount: "2", outstanding: "15000" },
];

const result = data.reduce(
  (acc, curr) => {
    const { totalaccount } = curr;
    if (totalaccount) {
      acc.push([]);
    } else {
      acc[acc.length - 1].push(curr);
    }
    return acc;
  },
  [[]]
);

const resultObj = {};
result.forEach((d, i) => {
  if (d.length) {
    resultObj[`collection${i + 1}`] = [...d];
  }
});
console.log(resultObj);

Answer 2

To accomplish this task, utilize the reduce function.

Start by checking for the presence of the totalaccount property. If it exists, create a new array within the accumulator (acc) using the push method of Array.prototype. If the totalaccount property does not exist, simply push the object into the last array of acc. Keep track of the index of the last array element with current

const data = [
  { loanname: "Mr X", acnumber: "020000000000001", outstanding: "54000" },
  { loanname: "Mrs Y", acnumber: "020000000000087", outstanding: "87000" },
  { loanname: "Mr Z", acnumber: "020000000000103", outstanding: "15000" },
  { totalaccount: "3", outstanding: "156000" },
  { loanname: "David", acnumber: "020000000000091", outstanding: "11000" },
  { loanname: "James", acnumber: "020000000001291", outstanding: "4000" },
  { totalaccount: "2", outstanding: "15000" },
];

let current = 0;
const result = data.reduce((acc, curr) => {
    const { totalaccount } = curr;
    if (totalaccount) {
      acc.push([]);
      ++current;
    } else {
      acc[current].push(curr);
    }
    return acc;
  },
  [[]]
);

const [first, second] = result;
console.log(first);
console.log(second);
console.log(result);

You can achieve the same outcome without explicitly tracking the current index as shown below:

const data = [
  { loanname: "Mr X", acnumber: "020000000000001", outstanding: "54000" },
  { loanname: "Mrs Y", acnumber: "020000000000087", outstanding: "87000" },
  { loanname: "Mr Z", acnumber: "020000000000103", outstanding: "15000" },
  { totalaccount: "3", outstanding: "156000" },
  { loanname: "David", acnumber: "020000000000091", outstanding: "11000" },
  { loanname: "James", acnumber: "020000000001291", outstanding: "4000" },
  { totalaccount: "2", outstanding: "15000" },
];

const result = data.reduce(
  (acc, curr) => {
    const { totalaccount } = curr;
    if (totalaccount) {
      acc.push([]);
    } else {
      acc[acc.length - 1].push(curr);
    }
    return acc;
  },
  [[]]
);

console.log(result);

If you wish to aggregate into a single object and dynamically create properties

const data = [
  { loanname: "Mr X", acnumber: "020000000000001", outstanding: "54000" },
  { loanname: "Mrs Y", acnumber: "020000000000087", outstanding: "87000" },
  { loanname: "Mr Z", acnumber: "020000000000103", outstanding: "15000" },
  { totalaccount: "3", outstanding: "156000" },
  { loanname: "David", acnumber: "020000000000091", outstanding: "11000" },
  { loanname: "James", acnumber: "020000000001291", outstanding: "4000" },
  { totalaccount: "2", outstanding: "15000" },
];

const result = data.reduce(
  (acc, curr) => {
    const { totalaccount } = curr;
    if (totalaccount) {
      acc.push([]);
    } else {
      acc[acc.length - 1].push(curr);
    }
    return acc;
  },
  [[]]
);

const resultObj = {};
result.forEach((d, i) => {
  if (d.length) {
    resultObj[`collection${i + 1}`] = [...d];
  }
});
console.log(resultObj);

Answer 3

Answer №2

Check out this potential solution (not fully tested yet, just a concept)

const myArray = [];
for (let index = 0; index < info.length; index++) {
  if (!info[index].currentBalance) continue;
    myArray.push([]);
    for (let y = index - info[index].currentBalance; y <= index - 1; y++) {
      myArray[myArray.length-1].push(info[y]);
    }
}
console.log(myArray);

Answer 4

Check out this potential solution (not fully tested yet, just a concept)

const myArray = [];
for (let index = 0; index < info.length; index++) {
  if (!info[index].currentBalance) continue;
    myArray.push([]);
    for (let y = index - info[index].currentBalance; y <= index - 1; y++) {
      myArray[myArray.length-1].push(info[y]);
    }
}
console.log(myArray);

Navigating through Javascript Arrays with Conditions to Separate Objects

Answer №1

Answer №2

Similar questions

"Customizing the MsAdalAngular6Module setup on the fly - a step-by-step

How to toggle the visibility of a div with multiple checkboxes using the iCheck plugin for jQuery

Find a specific number within an array using Javascript, and if it is not found, return the closest

How can I create a real-time page update using node.js?

Can an element be targeted for hover in CSS without it being a child element?

Dealing with an unexpected token error in JSON? Learn how to properly handle removing special characters like quotation marks and line breaks to

What is the best way to access a variable within an event handler function?

Translating PHP code into JavaScript

Restart following the execution of a Jquery function

Divide the controller functionality from the factory operations in Angular

What is the best way to retrieve data from this array?

Angular problem arises when attempting to map an array and selectively push objects into another array based on a specific condition

Executing .Net function in IronPython [Visual Studio 2012]

Guide to using normalize.css via npm installation with webpack

Repeating promises resolutions yields stagnant outcomes

Is there a way to create an input field that accepts only numbers and behaves like a password field simultaneously?

After deploying a NextJs app on Github Pages, only the readme file is displayed

What is the best approach to simultaneously update an array using multiple threads in a Node.js environment?

Encountering a TypeError stating that searchField.toLowerCase is not a function while employing hooks and redux in the

Is it possible to validate a mongoose array by comparing it with another array to check for common strings