Nodejs Array Filter customFilter(fn)

Method Source Code

/**/*from  w  w  w. j a v  a  2 s . c o m*/
 * Function takes a callback
 * @param fn => function
 */
Array.prototype.customFilter = function(fn) {
   let results = [];
    for (let i = 0; i < this.length; i++) {
        let itemExists = fn(this[i]);
        if (itemExists) {
            results.push(this[i]);
        }
    }
   return results;
};

Related

1. filter(predicateFunction)

   Array.prototype.filter = function(predicateFunction) {
     var results = [];
     this.forEach(function(item) {
       if (predicateFunction(item)) {
         results.push(item);
     });
     return results;
   

2. filter(search, func)

   Array.prototype.filter = function(search, func) {
     var results = [];
     for(var i = 0; i < this.length; i++) {
       if(func(search, this[i]))
          results.push(this[i]);
     return results;
   

3. filter(test)

   Array.prototype.filter = function (test) {
       var i, item, newArray = [];
       for (i = 0; i < this.length; i++) {
     item = this[i];
     if (test(item)) {
         newArray.push(item);
       return newArray;
   ...
   

4. filter(testFunction)

   Array.prototype.filter = function(testFunction){
     var result = [];
     this.forEach(function(item){
       if(testFunction(item)){
         result.push(item);
     })
     return result;
   

5. cs142filter(element, func)

   'use strict'
   Array.prototype.cs142filter = function(element, func) {
     var result = [];
     var array = Object(this);
     var length = array.length;
     for (var i = 0; i < length; i++) {
       var val = array[i];
       if (func.call(undefined, element, val)) {
         result.push(val);
   ...
   

6. filterByField(field, key)

   Array.prototype.filterByField = function(field, key) {
     var newArray = [];
     for (var i = 0; i < this.length; i++) {
       if (this[i][field] == key) {
         newArray.push(this[i]);
     return newArray;
   };
   ...
   

7. filterByField(field, value)

   Array.prototype.filterByField = function (field, value)
       var list = this;
       var listReturn = [];
       list.forEach(function(item)
           if (item[field] === value)
               listReturn.push(item);
   ...
   

8. filterEmpty()

   Array.prototype.filterEmpty = function ()
       var arr = this;
       var i = arr.length;
       while (i--)
           if (arr[i] instanceof Array)
               arr[i] = arr[i].filterEmpty();
   ...
   

9. filterSyncasync (callback, thisArg)

   Array.prototype.filterSync = async function (callback, thisArg) {
     let filterResult = await Promise.all(this.map(callback))
     return this.filter((_, index) => filterResult[index])