Nodejs Array Filter filterUnique()

Method Source Code

/*----------------------------------------------------------------------------*\
    # Copyright 2017, BuzzingPixel, LLC//from  ww w.  j  a v  a  2 s  .c  o m

    # This program is free software: you can redistribute it and/or modify
    # it under the terms of the Apache License 2.0.
    # http://www.apache.org/licenses/LICENSE-2.0
\*----------------------------------------------------------------------------*/

Array.prototype.filterUnique = function() {
    'use strict';

    var arr = [];
    var orig = this;

    orig.forEach(function(a, i) {
        if (arr.indexOf(a) < 0) {
            arr.push(a);
        } else {
            orig.splice(i, 1);
        }
    });

    return orig;
};

Array.prototype.getUnique = function() {
    'use strict';

    var arr = [];

    this.forEach(function(a) {
        if (arr.indexOf(a) < 0) {
            arr.push(a);
        }
    });

    return arr;
};

Array.prototype.pushUnique = function() {
    'use strict';

    for (var i = 0; i < arguments.length; ++i) {
        if (this.indexOf(arguments[i]) < 0) {
            this.push(arguments[i]);
        }
    }

    return this;
};

Related

1. customFilter(fn)

   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;
   ...
   

2. 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;
   };
   ...
   

3. 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);
   ...
   

4. filterEmpty()

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

5. filterSyncasync (callback, thisArg)

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

6. mfilter(fun)

   Array.prototype.mfilter =  function (fun) {
     var filtered = [];
     for(let i = 0; i < this.length; i++) {
       if (fun(this[i], i, this)) filtered.push(this[i]);
     return filtered;
   };
   var returnarr = [1,2,3,4,5,6].mfilter(function(element, index, arr) {
     return element > 5;
   ...
   

7. single(filter)

   Array.prototype.single = function(filter) {
     var matches = this.filter(filter);
     if (matches.length == 0) {
       throw new Error("Expected 1 but found 0");
     if (matches.length > 1) {
       throw new Error("Expected 1 but found many");
     return matches[0];
   ...
   

8. singleOrNone(filter)

   Array.prototype.singleOrNone = function(filter) {
     var matches = this.filter(filter);
     if (matches.length > 1) {
       throw new Error("Expected 1 but found many");
     if (matches.length == 0) {
       return null;
     return matches[0];
   ...