Array Cop

Array Cop is a dependency-free vanilla JS nano-library / npm module that deals with arrays. It is just an utility tool that makes life easier and also does some maths for you.

Current features:

• Flatten nested arrays
• Remove all the duplicates
• Pick any random item in any range
• Calculate the sum of all the Number items
• Calculate an Arithmetic mean
• Calculate a Geometric mean
• Calculate a Harmonic mean
• Find a median
• Convert to the frequency matrix object
• Log an array breakdown
• Remove all the empty items from the nested arrays
• Filter items in an array by type
• Convert an object into an array
• Get rid of all non-alphanumeric characters
• Get an array of indexes of an element

since version 0.5.0 minified js is not provided anymore. Use normal version in your browser or minify/concat during your usual production routine.

---

Usage

Browser

<script src = "array-cop.js">

npm

npm install array-cop

var array_ = require('array-cop');

---

API

var arr = [8, 1000,["Jack", 8, 'Bob', 'Alice', 5], 1, function x() {return 1 / x}, function a() {}, 2, [2, 3, 4, [5, 4, 6]], 7, 11, 7, [2], {
    x: 1,
    y: "test"
}];

I want to...

...flatten an array:

array_.flatten(arr);
Flattens an array to a single-dimensional one. Goes as deep into subarrays as needed.
array_.flatten(arr);

[ 8, 1000, 'Jack', 8, 'Bob', 'Alice', 5, 1, [Function: x], [Function: a], 2, 2, 3, 4, 5, 4, 6, 7, 11, 7, 2, { x: 1, y: 'test' } ]

...get rid of the duplicates:

array_.dedup(arr, [force]);
force: Boolean - Optional. Assign to true if you want to flatten an array and remove duplicates from the sub-arrays as well.
Removes duplicates from an array. Items in nested arrays are not treated as duplicates to avoid mess.
array_.dedup(arr);

[ 8, 1000, [ 'Jack', 8, 'Bob', 'Alice', 5 ], 1, [Function: x], [Function: a], 2, [ 2, 3, 4, [ 5, 4, 6 ] ], 7, 11, [ 2 ], { x: 1, y: 'test' } ]

array_.dedup(arr, true);

[ 1000, 'Jack', 8, 'Bob', 'Alice', 1, [Function: x], [Function: a], 3, 5, 4, 6, 11, 7, 2, { x: 1, y: 'test' } ]

...get a random array item:

array_.rand(arr,[min],[max]);
min, max: Number — Optional argument, set the range of items to choose from.
Randomly picks and returns one item from an array.
array_.rand(arr,3,8);

[Function: x]

...get a sum of all items:

array_.sum(arr);
Flattens an array and takes only numeric values into a consideration.
array_.sum(arr);

1075

...calculate an average:

array_.mean(arr, [type], [precision]);
type: String — Optional, sets the type of mean: 'ari': arithmetic, 'geo': geometric, 'har': harmonic. If omitted then calculates an arithmetic mean.
precision: Number — Optional argument, sets the number of digits after a decimal point. If omitted then falls back to 2.
Flattens an array and takes only numeric values into a consideration.
array_.mean(arr, 'geo', 3);

67.188

array_.mean(arr, 'ari', 2);

5.87

array_.mean(a, 4);

67.1875

...find a median:

array_.median(arr, [precision]);
precision: Number — Optional argument, sets the number of digits after a decimal point. If omitted then falls back to 2 Flattens an array and takes only numeric values into a consideration.
array_.median(arr, 1);

5.0

...get a frequency matrix:

array_.freq(arr)
Returns an object item: frequency, where item is the value of an each array item and frequency is the number of times that item appears in an array. Flattens an array before evaluation.
array_.freq(arr);

{ '1': 1,
'2': 3,
'3': 1,
'4': 2,
'5': 2,
'6': 1,
'7': 2,
'8': 2,
'11': 1,
'1000': 1,
Jack: 1,
Bob: 1,
Alice: 1,
'function x() {return 1 / x}': 1,
'function a() {}': 1,
'[object Object]': 1 }

...get an array breakdown:

array_.breakdown(arr, [toObject]);
toObject: Boolean — Optional argument, if set to true then method will return an object with items sorted by their type.
Service method. Result is an array console pretty print.

array_.breakdown(arr);

Numbers: 16
Strings: 3
Functions: 2
Objects: 1
Undefined: 0
Booleans: 0
Total items: 22

Note that by default you do not need to console.log breakdown() to have it printed out

array_.breakdown(arr, true);

{ number_: [ 8, 1000, 8, 5, 1, 2, 2, 3, 4, 5, 4, 6, 7, 11, 7, 2 ], string_: [ 'Jack', 'Bob', 'Alice' ], function_: [ [Function: x], [Function: a] ], object_: [ { x: 1, y: 'test' } ], undefined_: [], boolean_: [] }

...destroy all the empty items in an array:

array_.cop(arr, [toFlatten]);
toFlatten: Boolean — Optional argument. Flattens before all the work.
Goes on patrol and removes all the undefineds from an array preserving the structure.
array_.cop([1,2,,,,,3,4,[5,,,,,],6,,,,8,3,[[[],9]]]);

[ 1, 2, 3, 4, [ 5 ], 6, 8, 3, [ [ [ ], 9 ] ] ]

array_.cop([1,2,,,,,3,4,[5,,,,,],6,,,,8,3,[[[],9]]], true);

[ 1, 2, 3, 4, 5, 6, 8, 3, 9 ]

...filter an array by item type or remove some types:

array_.keep(arr, [type], [filter]);
type: String — sets the type of an object to work with. Values are:
'string', 'number', 'function', 'object', 'boolean', 'null', 'undefined'
Default value is 'string'
filter: String — sets the logic for the method.
'all' — keep all array items of type, remove the rest
'but' — keep all array items, but type
Default value is 'all'
array_.keep(arr, 'object', 'all');

[ { x: 1, y: 'test' } ]

array_.keep(arr);

[ 'Jack', 'Bob', 'Alice' ]

array_.keep(arr, 'number', 'but');

[ 'Jack', 'Bob', 'Alice', [Function: x], [Function: a], { x: 1, y: 'test' } ]

...remove non alphanumerics from the String items:

array_.alpha(arr);
array_.alphaNum(arr);
alpha() keeps letters only, alphaNum() saves digits as well.
Method ignores all non-String items to keep them safe. Multidimensional structure is preserved.

array_.alpha(["Clinton 2022", ["__jazzy cat.69", "'s t r\ni n g'"],[["catlady+01"], true]]);

[ 'Clinton', [ 'jazzycat', 'string' ], [ [ 'catlady' ], true ] ]

array_.alphaNum(["Clinton 2022", ["__jazzy cat.69", "'s t r\ni n g'"],[["catlady+01"], true]]);

[ 'Clinton2022', [ 'jazzycat69', 'string' ], [ [ 'catlady01' ], true ] ]

...convert an object into an array

array_.arrify(object)
Converts an object (associative array) into an array where object keys are array items.
Argument provided should be an object. Will throw an error if not an object type.
array_.arrify({name: 'Jack', id: 12345});

['Jack', 12345]

array_.arrify({name: 'Jack', id: 12345, record: [12, 23, 102]});

['Jack', 12345, [12, 23, 102]]

...get an array of indexes of a given element:

array_.index(arr, element, [preserveStructure])
Flattens an array and returns an array of index values.
element - mandatory. An element to look for in an array. If element does not exist then -1 is returned.
preserveStructure: Boolean - Optional, if set to true will not flatten an array and skip nested arrays.

var arr = ['Humpty','Dumpty', 'Sat', 'On', 'A', null, 'Humpty', 'Dumpty'];
var elem = "Humpty";
var indexList = array_.index(arr, elem);
indexList);

[ 0, 6 ]

array_.index([1, "String", , , 2, 'String', "", [eval('null;'), 2] ], 2 );

[ 2, 6 ] - flattening an array erases undefined elements!

array_.index([1, "String", , , 2, 'String', "", [eval('null;'), 2] ], 2, true );

[ 4 ]