A function to filter an array and map the result in one call.

Array.prototype.filterMap.js

Array.prototype.arrayMap = function(callback) {
  const newData = [];

  for (let i = 0; i < this.length; i++) {
    const entry = callback(this[i]);

    if (entry !== null && entry !== undefined) {
      newData.push(entry);
    }
  }

  return newData;
}