Nodejs Utililty Methods Array First or Default

Description

The list of methods to do Array First or Default are organized into topic(s).

Method

"use strict";
var firstOrDefault = function (array, expr) {
    if (typeof expr === "function") {
        array = array.filter(expr);
    return typeof array[0] === "undefined" ? null : array[0];
};
Array.prototype.firstOrDefault = function (expr) {
    return firstOrDefault(this, expr);
...

firstOrDefault(func)

Array.prototype.firstOrDefault = function(func) {
  var elements = this.filter(func)
  if (elements.length > 0)
    return elements[0]
  else
    return undefined

firstOrDefault(predicate)

Array.prototype.firstOrDefault = function (predicate) {
    if (predicate && typeof predicate === 'function') {
        for (var i = 0; i < this.length; i++) {
            if (predicate(this[i])) return this[i];
        return null;
    } else {
        return this.length > 0 ? this[0] : null;
};