Analyzing an array through its sub arrays

Question

Analyzing an array through its sub arrays

Imagine we are dealing with an array of varying length and we need to process it in chunks of maximum size 100, aiming to use the fewest number of chunks. For example, if the array's length is 241, we would need to divide it into 3 subarrays: 41, 100, and 100 (or 100, 100, 41).

curr_len = arr.length;
offset = curr_len%100;
doSomethingWithSubArray(arr.slice(offset))

for(j = offset; j <= curr_len; j = j+100){
    doSomethingWithSubArray(arr.slice(j,j+100))
}

There must be more elegant solutions to this problem, perhaps eliminating the need for a special case before the loop. Any suggestions?

javascript arrays

Answer 1

Answer №1

The final segment is anticipated to be smaller in size. In that case, the code would appear like this:

for (var i=0; i<arr.length; i+=100)
    doSomethingWithSubArray(arr.slice(i, 100));

This mirrors the functionality of my splitBy method:

Array.prototype.splitBy = function(n) {
/* obtain: number of elements per array
yield: array of n-sized arrays with the elements (last array might have less than n) */
    for (var r=[], i=0; i<this.length; i+=n)
        r.push(this.slice(i, i+n));
    return r;
}

Then you simply write:

arr.splitBy(100).forEach(doSomethingWithSubArray);

Answer 2

The final segment is anticipated to be smaller in size. In that case, the code would appear like this:

for (var i=0; i<arr.length; i+=100)
    doSomethingWithSubArray(arr.slice(i, 100));

This mirrors the functionality of my splitBy method:

Array.prototype.splitBy = function(n) {
/* obtain: number of elements per array
yield: array of n-sized arrays with the elements (last array might have less than n) */
    for (var r=[], i=0; i<this.length; i+=n)
        r.push(this.slice(i, i+n));
    return r;
}

Then you simply write:

arr.splitBy(100).forEach(doSomethingWithSubArray);

Answer 3

Answer №2

Implement the chunk function

function chunkArray(inputArray, size){
    for(let x, i = 0, c = -1, l = inputArray.length, newArr = []; i < l; i++)
        (x = i % size) ? newArr[c][x] = inputArray[i] : newArr[++c] = [inputArray[i]];
    return newArr;
}

console.log(chunkArray([10,20,30,40,50,60,70,80,90,100], 4));

Answer 4

Implement the chunk function

function chunkArray(inputArray, size){
    for(let x, i = 0, c = -1, l = inputArray.length, newArr = []; i < l; i++)
        (x = i % size) ? newArr[c][x] = inputArray[i] : newArr[++c] = [inputArray[i]];
    return newArr;
}

console.log(chunkArray([10,20,30,40,50,60,70,80,90,100], 4));

Answer 5

Answer №3

This code utilizes a functional style approach with recursive solutions. It avoids the use of variables, loops, and counts for a clearer implementation.

const splitArray = function(arr, n){
    if (arr.length == 0) return [];
    const head = arr.slice(0, n), rest = arr.slice(n);

    return [head].concat( splitArray(rest, n) );
};

console.log(splitArray([1,2,3,4,5,6,7,8,9,10], 3));

Answer 6

This code utilizes a functional style approach with recursive solutions. It avoids the use of variables, loops, and counts for a clearer implementation.

const splitArray = function(arr, n){
    if (arr.length == 0) return [];
    const head = arr.slice(0, n), rest = arr.slice(n);

    return [head].concat( splitArray(rest, n) );
};

console.log(splitArray([1,2,3,4,5,6,7,8,9,10], 3));

Answer 7

Answer №4

This is an example of how to use the reduce method in JavaScript:

var array = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11];

var splitArrays = array.reduce(function(arr, cur, i) {
    if (i % 3 === 0) arr.push([]);
    arr[i / 3 | 0].push(cur);
    return arr;
}, []);
//splitArrays looks like:
//[[1,2,3],[4,5,6],[7,8,9],[10,11]]

Here is a more generic function that can split an array into subarrays of a specified length:

function splitArray(array, num) {
    return array.reduce(function(arr, cur, i) {
        if (i % num === 0) arr.push([]);
        arr[i / num | 0].push(cur);
        return arr;
    }, []);
}

Answer 8

This is an example of how to use the reduce method in JavaScript:

var array = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11];

var splitArrays = array.reduce(function(arr, cur, i) {
    if (i % 3 === 0) arr.push([]);
    arr[i / 3 | 0].push(cur);
    return arr;
}, []);
//splitArrays looks like:
//[[1,2,3],[4,5,6],[7,8,9],[10,11]]

Here is a more generic function that can split an array into subarrays of a specified length:

function splitArray(array, num) {
    return array.reduce(function(arr, cur, i) {
        if (i % num === 0) arr.push([]);
        arr[i / num | 0].push(cur);
        return arr;
    }, []);
}

Answer 9

Answer №5

Revamp your doSomethingWithSubArray function by allowing it to take a starting index as a parameter and have it return the next unprocessed index. If there is no more work to be done, return null. Implement this as an "iterator" within a while loop. Perform any additional tasks, such as updating the user interface, immediately after calling this "iterator" within the while loop condition.

Answer 10

Revamp your doSomethingWithSubArray function by allowing it to take a starting index as a parameter and have it return the next unprocessed index. If there is no more work to be done, return null. Implement this as an "iterator" within a while loop. Perform any additional tasks, such as updating the user interface, immediately after calling this "iterator" within the while loop condition.

Analyzing an array through its sub arrays

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

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