USA Array 🇺🇸

Dumb name, useful package

A lightweight dependancy free module to enhance JavaScript's array functionality.

npm i unitedstatesofamerica

Creating a New Array 🇺🇸

Import the wrapper from the module to use the extended methods without exposing the methods to standard arrays

const usa = require('unitedstatesofamerica');

// Wrap array in wrapper
const choices = usa([10, 20, 30, 40, 50]);

// Access custom array methods
choices.shuffle(); // [30, 50, 10, 40, 20]

To create a new iterable USA Array of a set length without specifying the values contained, use the .withLength(n) method of the USA Array module.

const usa = require('unitedstatesofamerica');

// Using .withLength() to create an iterable array with a length of 5
const arr = usa.withLength(5); // Expected: [undefined, undefined, undefined, undefined, undefined]

// Able to access standard array methods
// Set each item in the array to a random value between 1 and 3
const randomValues = arr.map(() => Math.floor(Math.random() * 3) + 1);

console.log(randomValues); // Example: [ 3, 1, 2, 1, 2 ]

// Also able to access Array USA methods
randomValues.countOf(1); // Expected: 2

Extending Prototypes 🇺🇸

Optionally, invoke the .exposeProtos() method to expose all arrays to the extended methods.

require('unitedstatesofamerica').exposeProtos();

const choices = [10, 20, 30, 40, 50];

// Access custom array methods
choices.shuffle(); // [30, 50, 10, 40, 20]

Chaining 🇺🇸

All Array USA methods that return arrays will return a new instance of Array USA, so standard JS Array methods, as well as Array USA methods can be chained.

require('unitedstatesofamerica').exposeProtos();

const grades = ['80', '60', '76', '100', '58', '96', '92', '62', '78', '84'];

const sortedPassingGrades = grades
  .toNum() // ARRAY USA METHOD
  .filter((score) => score > 72) // STANDARD ARRAY METHOD
  .descending(); // ARRAY USA METHOD

console.log(sortedPassingGrades); // Expected: [100, 96, 92, 84, 80, 78, 76]

Array USA Methods 🇺🇸

Useful Methods 🇺🇸

• Shuffle
• Batch
• Replace
• Is Empty
• Last

Duplicate Management 🇺🇸

• Without Duplicates
• Duplicates

Copies 🇺🇸

• Copy
• Deep Copy

Random 🇺🇸

• Random
• Random Index

Counts 🇺🇸

• Count Of
• Count If

Sorting 🇺🇸

• Ascending
• Descending

Querying 🇺🇸

• Partial Match
• Partial Match Index

Math 🇺🇸

• Sum
• Difference
• Product
• Quotient
• Mean
• Average
• Median
• Mode

Type Management 🇺🇸

• Filter Type
• Types
• To Array
• To Str
• To Num

Filtering 🇺🇸

• Even Indexes
• Odd Indexes
• Without Null Values
• Without Falsy Values

Comparing 🇺🇸

• Assert

Conversion 🇺🇸

• To Object

Shuffle

.shuffle() will randomize the order of an array using the Fisher–Yates shuffle Algorithm

Example

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const options = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
const unshuffled = usa(options); // Use the spread operator to pass in an existing array
const shuffled = unshuffled.shuffle(); // Expected: array in randomized order, like [8,3,4,2,10,5,1,9,6,7]

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const unshuffled = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
const shuffled = unshuffled.shuffle(); // Expected: array in randomized order, like [8,3,4,2,10,5,1,9,6,7]

Without Duplicates

.withoutDuplicates() will return a new array without duplicate items

Example

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const users = usa(['Justin', 'Justin', 'Jack', 'Amanda', 'Mary', 'Amanda']); // Pass values directly into the wrapper
const uniqueUsers = users.withoutDuplicates(); // Expected: ["Justin", "Jack", "Amanda", "Mary"]

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const users = ['Justin', 'Justin', 'Jack', 'Amanda', 'Mary', 'Amanda'];
const uniqueUsers = users.withoutDuplicates(); // Expected: ["Justin", "Jack", "Amanda", "Mary"]

Duplicates

.duplicates() filters an array to include only items whose values appear more than once in the array.

Example

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const logins = usa(['Justin', 'Justin', 'Jack', 'Amanda', 'Mary', 'Amanda']);
const duplicateLogins = logins.duplicates(); // Expected: ["Justin", "Amanda"]

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const logins = ['Justin', 'Justin', 'Jack', 'Amanda', 'Mary', 'Amanda'];
const duplicateLogins = logins.duplicates(); // Expected: ["Justin", "Amanda"]

Batch

.batch(limit) will batch an array's elements into several nested arrays of a specified length.

Parameters

• limit (Integer) - Length of batch

Example

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const unbatched = ['Justin', 'Amanda', 'Mary', 'Kelly', 'Jonathan', 'Tom'];
const batched = usa(unbatched).batch(2); // Expected: [["Justin", "Amanda"], [ "Mary", "Kelly"], ["Jonathan", "Tom"]]

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const unbatched = ['Justin', 'Amanda', 'Mary', 'Kelly', 'Jonathan', 'Tom'];
const batched = unbatched.batch(2); // Expected: [["Justin", "Amanda"], [ "Mary", "Kelly"], ["Jonathan", "Tom"]]

Copy

.copy() will create a Shallow Copy of an array

Example

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const words = usa(['foo', 'bar', 'baz']);
const wordsCopy = words.copy(); // Expected: ["foo", "bar", "baz"]

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const words = ['foo', 'bar', 'baz'];
const wordsCopy = words.copy(); // Expected: ["foo", "bar", "baz"]

Deep Copy

.deepCopy() will make a Deep Copy of an array. This means objects or nested arrays will be replaced with replicated values, without referencing the original array. Changes can be made of the copied array without changing the original array.

Example

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const original = usa([
  { foo: 'bar', foobar: ['foo', 'bar'] },
  { bar: 'foo', barfoo: ['bar', 'foo'] },
  { foobar: ['foo', 'bar'] },
  30,
  20,
  'Why does this array have so many types',
  Symbol(),
  'Oh yeah, to show you how to it can make a deep copy of any type',
]);

const copied = original.deepCopy(); // Makes a deep copy

// Object reference comparison
copied[0].foo = 'baz';

console.log(original[0].foo === copied[0].foo); // Expected: false

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const original = [
  { foo: 'bar', foobar: ['foo', 'bar'] },
  { bar: 'foo', barfoo: ['bar', 'foo'] },
  { foobar: ['foo', 'bar'] },
  30,
  20,
  'Why does this array have so many types',
  Symbol(),
  'Oh yeah, to show you how to it can make a deep copy of any type',
];

const copied = original.deepCopy(); // Makes a deep copy

// Object reference comparison
copied[0].foo = 'baz';

console.log(original[0].foo === copied[0].foo); // Expected: false

Random

.random() will return a random item in the array

Example

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const words = usa(['foo', 'bar', 'baz']);
words.random(); // Expected Example: "bar"

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const words = ['foo', 'bar', 'baz'];
words.random(); // Expected Example: "bar"

Random Index

.randomIndex() returns a random index in the array

Example

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const words = usa(['foo', 'bar', 'baz']);
words.randomIndex(); // Expected Example: 2

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const words = ['foo', 'bar', 'baz'];
words.randomIndex(); // Expected Example: 2

Count Of

.countOf(val) will return a count of all items in an array matching a specified value.

Parameters

• val (any) - Value to match

Example

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const words = usa(['foo', 'bar', 'foo', 'foo', 'baz']);
const fooCount = words.countOf('foo'); // Expected: 3

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const words = ['foo', 'bar', 'foo', 'foo', 'baz'];
const fooCount = words.countOf('foo'); // Expected: 3

Count If

.countIf(condition) will return a count of all items in an array that when passed into a callback function, return true

Parameters

• condition (Function) - Callback function. For checking condition, takes in 3 parameters
  • item - (any) Item in the array
  • index - Optional (Integer) - Current index in the array
  • arr - Optional (Array) - Current array

Example

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const grades = usa([99, 93, 60, 70, 100, 80, 78, 100, 98, 94]);
const over90 = grades.countIf((grade) => grade >= 90); // Expected: 6

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const grades = [99, 93, 60, 70, 100, 80, 78, 100, 98, 94];
const over90 = grades.countIf((grade) => grade >= 90); // Expected: 6

Last

.last() returns the last item in the array

Example

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const users = usa(['Jack', 'Jill', 'Bob', 'Joe']);
const lastUser = users.last(); // Expected: Joe

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const users = ['Jack', 'Jill', 'Bob', 'Joe'];
const lastUser = users.last(); // Expected: Joe

Ascending

.ascending() sorts the array in ascending order

Example

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const grades = usa([99, 93, 60, 70, 100, 80, 78, 100, 98, 94]);
const worstToBest = grades.ascending(); // Expected: [60, 70, 78, 80, 93,94, 98, 99, 100, 100]

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const grades = [99, 93, 60, 70, 100, 80, 78, 100, 98, 94];
const worstToBest = grades.ascending(); // Expected: [60, 70, 78, 80, 93,94, 98, 99, 100, 100]

Descending

.descending() sorts the array in descending order

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const grades = usa([99, 93, 60, 70, 100, 80, 78, 100, 98, 94]);
const bestToWorst = grades.descending(); // Expected: [100, 100, 99, 98, 94, 93, 80, 78, 70, 60]

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const grades = [99, 93, 60, 70, 100, 80, 78, 100, 98, 94];
const bestToWorst = grades.descending(); // Expected: [100, 100, 99, 98, 94, 93, 80, 78, 70, 60]

Is Empty

.isEmpty() is a simple method that returns true if the specified array's length is 0.

Example

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const arr1 = usa([]);
const arr2 = usa(['foo', 'bar', 'baz']);

console.log(arr1.isEmpty()); // Expected: true
console.log(arr2.isEmpty()); // Expected: false

arr1.push('foobar');

console.log(arr1.isEmpty()); // Expected: false

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const arr1 = [];
const arr2 = ['foo', 'bar', 'baz'];

console.log(arr1.isEmpty()); // Expected: true
console.log(arr2.isEmpty()); // Expected: false

Partial Match

.partialMatch(obj) finds the first item matching the key/value pairs of the object passed in.

Parameters

• obj (Object) - Object containing key/value pairs of array item to find

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const users = usa([
  {
    firstName: 'Jon',
    lastName: 'Smith',
    email: '[email protected]',
  },
  {
    firstName: 'Jane',
    lastName: 'Doe',
    email: '[email protected]',
  },
  {
    firstName: 'Elon',
    lastName: 'Musk',
    email: '[email protected]',
  },
]);

const person = users.partialMatch({ email: '[email protected]' });
// Expected:
//  {
//    firstName: "Jane",
//    lastName: "Doe",
//    email: "[email protected]",
//  },

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const users = [
  {
    firstName: 'Jon',
    lastName: 'Smith',
    email: '[email protected]',
  },
  {
    firstName: 'Jane',
    lastName: 'Doe',
    email: '[email protected]',
  },
  {
    firstName: 'Elon',
    lastName: 'Musk',
    email: '[email protected]',
  },
];

const person = users.partialMatch({ email: '[email protected]' });
// Expected:
//  {
//    firstName: "Jane",
//    lastName: "Doe",
//    email: "[email protected]",
//  },

Partial Match Index

.partialMatch(obj) finds the first index matching the key/value pairs of the object passed in.

Parameters

• obj (Object) - Object containing key/value pairs of array item to find

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const users = usa([
  {
    firstName: 'Jon',
    lastName: 'Smith',
    email: '[email protected]',
  },
  {
    firstName: 'Jane',
    lastName: 'Doe',
    email: '[email protected]',
  },
  {
    firstName: 'Elon',
    lastName: 'Musk',
    email: '[email protected]',
  },
]);

const person = users.partialMatchIndex({ email: '[email protected]' }); // Expected: 1

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const users = [
  {
    firstName: 'Jon',
    lastName: 'Smith',
    email: '[email protected]',
  },
  {
    firstName: 'Jane',
    lastName: 'Doe',
    email: '[email protected]',
  },
  {
    firstName: 'Elon',
    lastName: 'Musk',
    email: '[email protected]',
  },
];

const person = users.partialMatchIndex({ email: '[email protected]' }); // Expected: 1

Without Nullish Values

.withoutNullishValues() will return a new array without nullish values (null and undefined)

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const arr1 = [3, 4, 'foo', 'bar', null, 'baz', false, 'foobar', NaN, undefined, ''];

const cleaned = usa(arr1).withoutNullishValues(); // Expected: [ 3, 4, 'foo', 'bar', 'baz', false, 'foobar', NaN ]

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const arr1 = [3, 4, 'foo', 'bar', null, 'baz', false, 'foobar', NaN, undefined, ''];

const cleaned = arr1.withoutNullishValues(); // Expected: [ 3, 4, 'foo', 'bar', 'baz', false, 'foobar', NaN ]

Without Falsy Values

.withoutFalsyValues() will return a new array without any falsy values from the array

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const arr1 = [3, 4, 'foo', 'bar', null, 'baz', false, 'foobar', NaN, undefined, ''];

const cleaned = usa(arr1).withoutFalsyValues(); // Expected: [ 3, 4, 'foo', 'bar', 'baz', 'foobar']

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const arr1 = [3, 4, 'foo', 'bar', null, 'baz', false, 'foobar', NaN, undefined, ''];

const cleaned = arr1.withoutFalsyValues(); // Expected: [ 3, 4, 'foo', 'bar', 'baz', 'foobar']

Sum

.sum() returns the sum of all items in a numerical array.

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const nums = usa([10, 20, 30]);
nums.sum(); // Expected: 60

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const nums = [10, 20, 30];
nums.sum(); // Expected: 60

Difference

.difference() returns the difference of all items in a numerical array.

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const nums = usa([10, 20, 30]);
nums.difference(); // Expected: -40

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const nums = [10, 20, 30];
nums.difference(); // Expected: -40

Product

.product() returns the product of all items in a numerical array.

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const nums = usa([10, 20, 30]);
nums.product(); // Expected: 6000

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const nums = [10, 20, 30];
nums.product(); // Expected: 6000

Quotient

.quotient() returns the quotient of all items in a numerical array.

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const nums = usa([10, 20, 30]);
nums.quotient(); // Expected: 0.016666666666666666

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const nums = [10, 20, 30];
nums.quotient(); // Expected: 0.016666666666666666

Mean

.mean() returns the average for an array. Note: This will return NaN if all items in an array are not numbers

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const projectGrades = usa([90, 100, 80, 100, 100]);
const averageGrage = projectGrades.average(); // Expected: 94

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const projectGrades = [90, 100, 80, 100, 100];
const averageGrage = projectGrades.average(); // Expected: 94

Average

.average() is an alternate term for .mean()

Median

.median() returns the median of all items in the array

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const nums = usa([10, 20, 30, 50, 100]);
nums.median(); // Expected: 30

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const nums = [10, 20, 30, 50, 100];
nums.median(); // Expected: 30

Mode

.mode() returns the mode of the array

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const nums = usa([10, 20, 30, 50, 100]);
nums.mode(); // Expected: 20

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const nums = [10, 20, 20, 30, 50, 100];
nums.mode(); // Expected: 20

Replace

.replace() replaces all occurances of a specified value with a new value.

Parameters

• oldVal (Any) - Value to replace
• newVal (Any) - Replacement value

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const arr = usa(['foo', 'bar', 'foobar', 'bar', 'foo']);
const noFoo = arr.replace('foo', 'baz'); // Expected: ["baz", "bar", "foobar", "bar", "baz"]

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const arr = ['foo', 'bar', 'foobar', 'bar', 'foo'];
const noFoo = arr.replace('foo', 'baz'); // Expected: ["baz", "bar", "foobar", "bar", "baz"]

Filter Type

.filterType() filters an array to only a specified type

Parameters

• type (String) - String representing JS type

Possible Types

• "string"
• "number"
• "boolean"
• "undefined"
• "symbol"
• "function"
• "object" - Returns all JS object types (objects, arrays, functions, null)
• "array" - Returns only nested arrays
• "null" - Returns only null values
• "objectOnly" - Returns only objects without returning arrays

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const arr = [1, 4, 't', ['nested', 8], { foo: 'bar' }, { baz: false }, [1, 2, 3], true, ''];
const mixed = usa(arr); // Spread syntax can be used to convert an existing array

// Only strings
const strOnly = mixed.filterType('string'); // Expected: ["t", ""]

// Only arrays
const nestedArrsOnly = mixed.filterType('array'); // [["nested", 8], [1,2,3]]

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const mixed = [1, 4, 't', ['nested', 8], { foo: 'bar' }, { baz: false }, [1, 2, 3], true, ''];

// Only strings
const strOnly = mixed.filterType('string'); // Expected: ["t", ""]

// Only arrays
const nestedArrsOnly = mixed.filterType('array'); // [["nested", 8], [1,2,3]]

Types

.types() returns an array of the target array's types.

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const mixed = usa([1, 4, 't', true, '']);
const types = mixed.types(); // Expected: ["number", "number", "string", "boolean", "string"]

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const mixed = [1, 4, 't', true, ''];
const types = mixed.types(); // Expected: ["number", "number", "string", "boolean", "string"]

To Array

.toArray() returns your ArrayUSA array as a standard JavaScript array;

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const arr = [5, 1, 2, 2, 5, 3, 3, 4, 5];
const noDuplicates = usa(arr)
  .withoutDuplicates() // Remove duplicates
  .toArray(); // Convert ArrayUSA array to a standard JavaScript array

noDuplicates.shuffle(); // ❌ ArrayUSA methods no longer work

To Str

.toStr() returns an array of a string version of all the items in the array. Note: Conversion is different depending on type. For example, objects and arrays will be returned stringified.

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const arr = [1, 4, 't', ['nested', 8], { foo: 'bar' }, { baz: false }, [1, 2, 3], true];
const mixed = usa(arr); // Spread syntax can be used to convert an existing array

const strArr = mixed.toStr(); // ['1','4','t','["nested",8]','{"foo":"bar"}','{"baz":false}','[1,2,3]','true']

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const mixed = [1, 4, 't', ['nested', 8], { foo: 'bar' }, { baz: false }, [1, 2, 3], true];
const strArr = mixed.toStr(); // ['1','4','t','["nested",8]','{"foo":"bar"}','{"baz":false}','[1,2,3]','true']

To Num

.toNum() returns a new array with all items converted to numbers.

Parameters

base - Base to parse numbers to. (Defaults to 10)

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const arr = ['1', 4, '3.2', '7', '19', 0];
usa(arr).toNum(); // Expected: [1, 4, 3.2, 7, 19, 0]

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const arr = ['1', 4, '3.2', '7', '19', 0];
arr.toNum(); // Expected: [1, 4, 3.2, 7, 19, 0]

Even Indexes

.evenIndexes() returns only the even index items in an array

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const arr = ['foo', 'bar', 'baz', 'foobar'];
usa(arr).evenIndexes(); // Expected: ["foo", "baz"]

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const arr = ['foo', 'bar', 'baz', 'foobar'];
arr.evenIndexes(); // Expected: ["foo", "baz"]

Odd Indexes

.oddIndexes() returns only the odd index items in an array

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const arr = ['foo', 'bar', 'baz', 'foobar'];
usa(arr).oddIndexes(); // Expected: ["bar", "foobar"]

Extending Prototype

require('unitedstatesofamerica').exposeProtos();

const arr = ['foo', 'bar', 'baz', 'foobar'];
arr.oddIndexes(); // Expected: ["bar", "foobar"]

Assert

.assert() does a deep compare on an array with any target array - Returning a boolean of if all values and nested values matched.

Examples

Array USA Wrapper

const usa = require('unitedstatesofamerica');

const a1 = [{ foo: 'bar', bar: 4, baz: false }, [4, 3, 2, 1], 'f', 0, true, 'i'];
const a2 = [{ foo: 'bar', bar: 4, baz: false }, [4, 3, 2, 1], 'f', 0, true, 'i'];

usa(a1).assert(a2); // Expected: true

const a3 = [{ foo: 'baz', bar: 4, baz: false, t: 4 }, [4, 3, 2, 1], 'j', 1, true, 'i'];
const a4 = [{ foo: 'bar', bar: 4, baz: false }, [4, 3, 2, 1], 'f', 0, true, 'i'];

usa(a3).assert(a4); // Expected: false

Extending Prototype

const usa = require('unitedstatesofamerica').exposeProtos();

const a1 = [{ foo: 'bar', bar: 4, baz: false }, [4, 3, 2, 1], 'f', 0, true, 'i'];
const a2 = [{ foo: 'bar', bar: 4, baz: false }, [4, 3, 2, 1], 'f', 0, true, 'i'];

a1.assert(a2); // Expected: true

const a3 = [{ foo: 'baz', bar: 4, baz: false, t: 4 }, [4, 3, 2, 1], 'j', 1, true, 'i'];
const a4 = [{ foo: 'bar', bar: 4, baz: false }, [4, 3, 2, 1], 'f', 0, true, 'i'];

a3.assert(a4); // Expected: false

To Object

.toObject() converts an array to an object, with specified keys and values for each item

Parameters

• cb - OPTIONAL - Callback function called for each item in the array. Must return an object with a key key and a value key Note: Callback function is optional. It is not needed if every item in the array is an object with a key key and value key. Callback Parameters
  • Array item
  • Item Index
  • Array

Examples

Array USA Wrapper

Example 1: With Callback Function

const usa = require('unitedstatesofamerica');

const data = [
  { id: 'abc123', score: 97 },
  { id: 'def456', score: 82 },
  { id: 'hij789', score: 90 },
  { id: 'klm012', score: 78 },
];

// Expected: { abc123: 97, def456: 82, hij789: 90, klm012: 78 }
const scores = usa(data).toObject((item) => ({ key: item.id, value: item.score }));

Example 2: Without Callback Function

const usa = require('unitedstatesofamerica');

// If array is already in [{ key, value }] format
// No callback function is required to convert to an object
const houseAttributes = [
  { key: 'sqFt', value: 2000 },
  { key: 'yearBuilt', value: 1998 },
  { key: 'bedrooms', value: 4 },
  { key: 'bathrooms', value: 2.5 },
];

// Expected: { sqFt: 2000, yearBuilt: 1998, bedrooms: 4, bathrooms: 2.5 }
const home = usa(houseAttributes).toObject();

Extending Prototype

Example 1: With Callback Function

const usa = require('unitedstatesofamerica').exposeProtos();

const data = [
  { id: 'abc123', score: 97 },
  { id: 'def456', score: 82 },
  { id: 'hij789', score: 90 },
  { id: 'klm012', score: 78 },
];

// Expected: { abc123: 97, def456: 82, hij789: 90, klm012: 78 }
const scores = data.toObject((item) => ({ key: item.id, value: item.score }));

Example 2: Without Callback Function

const usa = require('unitedstatesofamerica');

// If array is already in [{ key, value }] format
// No callback function is required to convert to an object
const houseAttributes = [
  { key: 'sqFt', value: 2000 },
  { key: 'yearBuilt', value: 1998 },
  { key: 'bedrooms', value: 4 },
  { key: 'bathrooms', value: 2.5 },
];

// Expected: { sqFt: 2000, yearBuilt: 1998, bedrooms: 4, bathrooms: 2.5 }
const home = houseAttributes.toObject();