@selfcommunity/utils/lib/esm/utils/array.js

Utilities to integrate a Community.

/**
 * Check if two arrays are equal
 * @param a
 * @param b
 * @return boolean
 */
export const arraysEqual = (a, b) => {
    if (a === b)
        return true;
    if (a == null || b == null)
        return false;
    if (a.length !== b.length)
        return false;
    // If you don't care about the order of the elements inside
    // the array, you should sort both arrays here.
    // Please note that calling sort on an array will modify that array.
    // you might want to clone your array first.
    for (let i = 0; i < a.length; ++i) {
        if (a[i] !== b[i])
            return false;
    }
    return true;
};
/**
 * Group items from an array together by some criteria or value.
 * @param  {Array}           arr      The array to group items from
 * @param  {String|Function} criteria The criteria to group by
 * @return {Object}                   The grouped object
 */
export const groupBy = (arr, criteria) => {
    return arr.reduce(function (obj, item) {
        // Check if the criteria is a function to run on the item or a property of it
        let key = typeof criteria === 'function' ? criteria(item) : item[criteria];
        // If the key doesn't exist yet, create it
        // eslint-disable-next-line no-prototype-builtins
        if (!obj.hasOwnProperty(key)) {
            obj[key] = [];
        }
        // Push the value to the object
        obj[key].push(item);
        // Return the object to the next item in the loop
        return obj;
    }, {});
};
/**
 * Sort an array of objects by attr.
 * @param arr The array to group items from
 * @param attr Order attribute
 * @param asc Sort asc/desc
 */
export const sortByAttr = (arr, attr, asc = true) => {
    if (!Array.isArray(arr)) {
        return arr;
    }
    const f = asc
        ? (a, b) => a[attr] - b[attr]
        : (a, b) => b[attr] - a[attr];
    return arr.sort(f);
};