partition.js

/**
 * Partition array based on conditions
 * @param {Array} arr - Array
 * @param {Function} fn - Function to satisfy
 * @returns {Array} Partitioned array
 */
function partition(arr, fn) {
    let result = [[],[]];
    
    for (let i = 0; i < arr.length; i++) {
        result[fn(arr[i]) ? 0 : 1].push(arr[i]);
    }
    
    return result;
}