Nodejs Array Check isArray(obj)

Method Source Code

Array.isArray = Array.isArray || function (obj) {
   return {}.call(obj) === '[object Array]';
};

Related

1. is(that)

   Array.prototype.is = function(that) {
     var i, len, ok = true;
     for (i = 0, len = this.length; i < len && ok; i++) {
       if (this[i] instanceof Array && that[i] instanceof Array) {
         ok = this[i].is(that[i]);
       } else {
         ok = this[i] === that[i];
     return ok;
   };
   

2. isAllNegative()

   function maxSubArray (array) {
     var maxSoFar = 0,
         maxSum = 0;
     if (array.isAllNegative()) {
       var maxNum = Number.NEGATIVE_INFINITY;
       for (var j = 0, jLen = array.length; j < jLen; j++) {
         if (array[j] > maxNum) {
           maxNum = array[j]
       return maxNum;
     for (var i = 0, len = array.length; i < len; i++) {
       maxSoFar += array[i];
       if (maxSoFar < 0) {
         maxSoFar = 0;
       else if (maxSoFar > maxSum) {
         maxSum = maxSoFar;
     return maxSum;
   Array.prototype.isAllNegative = function () {
     for (var i = 0, len = this.length; i < len; i++) {
       if (this[i] >= 0) {
         return false;
     return true;
   var myArray = [-100,-2,-3,-4,-105,-104];
   maxSubArray(myArray);
   

3. isBlank()

   function proxy(func, context, args) {
       return function () {
           return func.apply(context, args);
   Array.prototype.isBlank = function () {
       return !this.length;
   };
   

4. isCharPresent(charSearch)

   Array.prototype.isCharPresent = function(charSearch) {
     var arr = this;
     var result = [];
     var testingStr = '';
     if (charSearch.length > 1) {
       return "You're searching for more than one char";
     for (var i = 0; i < this.length; i++) {
       if (arr[i].indexOf(charSearch) === -1) {
   ...
   

5. isDefined(key)

   Array.prototype.isDefined = function (key) {
       return this.filter(c => {
           if (key) return c[key];
           return !!c;
       });
   

6. isDistinct()

   Array.prototype.isDistinct = function() {
     this.sort();
     for (var i = 1; i < this.length; i++) {
       if (this[i - 1] == this[i])
         return false;
     return true;
   };