Persisting the tally of iterations in an array

Question

Persisting the tally of iterations in an array

When working in Javascript, I have a simple for loop that increments based on a variable num, which can be any input number:

const sequenceArr = [];

  for (let i = 0; i <= num; i++) {
    const addedSum = i + i;

    sequenceArr.push({ i, addedSum });
  }

For example, if num is set to 1000, an array of objects up to 1000 will be generated where each object looks like this:

[{1, 2}, {2, 4}, {3, 6} ... {1000, 2000} ]

. If we need to extend the count to 2000, currently the for loop starts over from 0 and repeats the same operations on numbers it has already encountered. This approach seems inefficient. How can I continue the count from, say, 1001 (or the last number in sequenceArr) instead of starting fresh from 0 and counting all the way up to 2000? Would sending data to a backend and importing a JSON file help with this situation? How could I implement such a solution?

This question relates to a small side project where I am counting up to a certain number so I can perform the addedSum operation on i. Upon further inspection, it is clear that the sequenceArr remains constant, so there's no need to recalculate the same numbers repeatedly. Instead, existing numbers should be used if num is less than the length of our array, while new numbers should only be generated when necessary.

In order to update the sequence with any new continuations of the count, these additional numbers would need to be pushed or updated in the sequenceArr.

javascript arrays for-loop count iterator

Answer 1

Answer №1

To add objects to an array based on the given items, you can create a function that iterates through the array and adds objects accordingly.

function addValuesToArray(array, num) {
    for (let i = array.length ? array[array.length - 1].i + 1 : 0; i <= num; i++) {
        const addedValue = i + i;
        array.push({ i, addedValue });
    }
}
  
const valuesArray = [];

addValuesToArray(valuesArray, 3);
console.log(valuesArray);

addValuesToArray(valuesArray, 5);
console.log(valuesArray);

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

Answer 2

To add objects to an array based on the given items, you can create a function that iterates through the array and adds objects accordingly.

function addValuesToArray(array, num) {
    for (let i = array.length ? array[array.length - 1].i + 1 : 0; i <= num; i++) {
        const addedValue = i + i;
        array.push({ i, addedValue });
    }
}
  
const valuesArray = [];

addValuesToArray(valuesArray, 3);
console.log(valuesArray);

addValuesToArray(valuesArray, 5);
console.log(valuesArray);

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

Answer 3

Answer №2

Just made a small tweak in your code.

let seriesArr = []; 

function getOutput(arr, num) {
  let length = arr.length;
    for ( length ? arr[length - 1].length + 1 : 0; length <= num; length++) {
        let sumAdded = length + length;
        arr.push({ length, sumAdded });
    }
}
  

getOutput(seriesArr, 3);
console.log(seriesArr);

getOutput(seriesArr, 5);
console.log(seriesArr);

Answer 4

Just made a small tweak in your code.

let seriesArr = []; 

function getOutput(arr, num) {
  let length = arr.length;
    for ( length ? arr[length - 1].length + 1 : 0; length <= num; length++) {
        let sumAdded = length + length;
        arr.push({ length, sumAdded });
    }
}
  

getOutput(seriesArr, 3);
console.log(seriesArr);

getOutput(seriesArr, 5);
console.log(seriesArr);

Persisting the tally of iterations in an array

Answer №1

Answer №2

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