ArrayHelpers

Array Methods Helpers

Description:

  • Array Methods Helpers

Methods

(static) addItemToAnArray(arr, item) → {Array|undefined}

Add an item to the end of an array

.

Description:

  • Add an item to the end of an array

Example
addItemToAnArray([1, 2], 3) => [1, 2, 3]

addItemToAnArray(["a"], "b") => ["a", "b"]

addItemToAnArray([], { id: 1 }) => [{ id: 1 }]

addItemToAnArray("not an array", 1) => undefined

addItemToAnArray([1, 2], true) => [1, 2, true]
Parameters:
Name Type Description
arr Array

The array to which the item will be added
item Number | Object | String | Boolean

The item to add to the array
Returns:

Returns the updated array, or undefined if input is invalid

Type
Array | undefined

(static) addItemsInFrontToAnArray(arr, items) → {Array|undefined}

Add one or more items to the beginning of an array

.

Description:

  • Add one or more items to the beginning of an array

Example
addItemsInFrontToAnArray([3, 4], 1, 2) => [1, 2, 3, 4]

addItemsInFrontToAnArray(["b", "c"], "a") => ["a", "b", "c"]

addItemsInFrontToAnArray([], 1, 2) => [1, 2]

addItemsInFrontToAnArray("not an array", 1) => undefined
Parameters:
Name Type Description
arr Array

The array to which items will be added
items any

One or more items to add at the beginning of the array
Returns:

Returns the updated array, or undefined if input is not an array

Type
Array | undefined

(static) addOrRemoveItemsByIndex(arr, startIndex, count, items) → {Array|undefined}

Add or remove items from an array by index

.

Description:

  • Add or remove items from an array by index

Example
addOrRemoveItemsByIndex([1, 2, 3, 4], 1, 2) => [1, 4]

addOrRemoveItemsByIndex([1, 2, 3], 1, 1, "a", "b") => [1, "a", "b", 3]

addOrRemoveItemsByIndex([1, 2, 3], 1, 0, "a") => [1, "a", 2, 3]

addOrRemoveItemsByIndex("not an array", 1, 1) => undefined
Parameters:
Name Type Description
arr Array

The array to modify
startIndex Number

The index at which to start changing the array
count Number

Number of items to remove
items any

Items to add at the given index
Returns:

Returns the updated array, or undefined if input is invalid

Type
Array | undefined

(static) checkIsAllMatched(arr, condition, callbackopt) → {Boolean|undefined}

Check if all items in an array match a condition or callback

.

Description:

  • Check if all items in an array match a condition or callback

Example
checkIsAllMatched([2, 2, 2], 2) => true

checkIsAllMatched([{a:1}, {a:1}], {a:1}) => true

checkIsAllMatched([1, 2, 3, 4], null, (item) => item > 0) => true

checkIsAllMatched([1, 2, 3], 2) => false

checkIsAllMatched("not an array", 1) => undefined
Parameters:
Name Type Attributes Description
arr Array

The array to check
condition any | Object

Primitive value or object key-value to match
callback function <optional>

Optional function to decide if an item matches (must return boolean)
Returns:

Returns true if all items match, false if not, undefined if input invalid

Type
Boolean | undefined

(static) checkIsMatched(arr, condition, callbackopt) → {Boolean|undefined}

Check if an array has at least one item matching a condition or callback

.

Description:

  • Check if an array has at least one item matching a condition or callback

Example
checkIsMatched([1, 2, 3], 2) => true

checkIsMatched([{a:1}, {a:2}], {a:1}) => true

checkIsMatched([1, 2, 3, 4], null, (item) => item % 2 === 0) => true

checkIsMatched([1, 2, 3], 4) => false

checkIsMatched("not an array", 1) => undefined
Parameters:
Name Type Attributes Description
arr Array

The array to search
condition any | Object

Primitive value or object key-value to match
callback function <optional>

Optional function that decides if an item matches (must return boolean)
Returns:

Returns true if at least one item matches, false if none match, undefined if input invalid

Type
Boolean | undefined

(static) countItem(arr, keyOfCountopt, initialValueopt) → {Number|undefined}

Count or sum items in an array, optionally by key for objects

.

Description:

  • Count or sum items in an array, optionally by key for objects

Example
countItem([1, 2, 3]) => 6

countItem([{a:1}, {a:2}, {a:3}], "a") => 6

countItem([{a:1}, {a:2}, {b:3}], "a") => 3

countItem("not an array") => undefined
Parameters:
Name Type Attributes Default Description
arr Array

The array to process
keyOfCount String <optional>

Optional key to sum values from objects
initialValue Number <optional>
 0

Optional starting value
Returns:

Returns the total count/sum, or undefined if input invalid

Type
Number | undefined

(static) filterAnArray(arr, condition, callbackopt) → {Array|undefined}

Filter an array by a condition (primitive or object key-value) with optional callback

.

Description:

  • Filter an array by a condition (primitive or object key-value) with optional callback

Example
filterAnArray([1, 2, 3, 2], 2) => [2, 2]

filterAnArray([{a:1}, {a:2}], {a:1}) => [{a:1}]

filterAnArray([1, 2, 3, 4], null, (item) => item % 2 === 0) => [2, 4]
Parameters:
Name Type Attributes Description
arr Array

The array to filter
condition any | Object

Value to filter by, or object with key-value pairs
callback function <optional>

Optional function to decide if an item should be kept (must return boolean)
Returns:

Returns filtered array, or undefined if input is invalid

Type
Array | undefined

(static) findArrayByItem(arr, condition, callbackopt) → {any|undefined}

Find the first item in an array that matches a condition or callback

.

Description:

  • Find the first item in an array that matches a condition or callback

Example
findArrayByItem([1, 2, 3], 2) => 2

findArrayByItem([{a:1}, {a:2}], {a:1}) => {a:1}

findArrayByItem([1, 2, 3, 4], null, (item) => item % 2 === 0) => 2

findArrayByItem([1, 2, 3], 4) => undefined

findArrayByItem("not an array", 1) => undefined
Parameters:
Name Type Attributes Description
arr Array

The array to search
condition any | Object

Primitive value or object key-value to match
callback function <optional>

Optional function to decide if an item matches (must return boolean)
Returns:

Returns the first matched item, or undefined if none found or input invalid

Type
any | undefined

(static) findIndexArrayItem(arr, condition, callbackopt) → {Number|undefined}

Find the index of the first item in an array that matches a condition or callback

.

Description:

  • Find the index of the first item in an array that matches a condition or callback

Example
findIndexArrayItem([1, 2, 3], 2) => 1

findIndexArrayItem([{a:1}, {a:2}], {a:2}) => 1

findIndexArrayItem([1, 2, 3, 4], null, (item) => item % 2 === 0) => 1

findIndexArrayItem([1, 2, 3], 4) => -1

findIndexArrayItem("not an array", 1) => undefined
Parameters:
Name Type Attributes Description
arr Array

The array to search
condition any | Object

Primitive value or object key-value to match
callback function <optional>

Optional function to decide if an item matches (must return boolean)
Returns:

Returns the index of the first matched item, -1 if not found, or undefined if input invalid

Type
Number | undefined

(static) flatAnArray(arr, depthopt) → {Array|undefined}

Flatten an array up to a specified depth

.

Description:

  • Flatten an array up to a specified depth

Example
flatAnArray([1, [2, 3], [4, [5]]]) => [1, 2, 3, 4, [5]]

flatAnArray([1, [2, [3, 4]]], 2) => [1, 2, 3, 4]

flatAnArray("not an array") => undefined
Parameters:
Name Type Attributes Default Description
arr Array

The array to flatten
depth Number <optional>
 1

Depth level specifying how deep a nested array should be flattened
Returns:

Returns a new flattened array, or undefined if input invalid

Type
Array | undefined

(static) getArrayLength(arr) → {Number|undefined}

Check the array Length

.

Description:

  • Check the array Length

Example
getArrayLength([1, 2]) => 2

getArrayLength([]) => 0

getArrayLength({}) => undefined

getArrayLength("hello") => undefined

getArrayLength(123) => undefined

getArrayLength(true) => undefined

getArrayLength(Infinity) => undefined

getArrayLength(NaN) => undefined

getArrayLength(() => {}) => undefined

getArrayLength(null) => undefined
Parameters:
Name Type Description
arr Array

To get the length of the array
Returns:

Returns the Array lenght number, undefined if user input is not an array

Type
Number | undefined

(static) getItemByIndex(userArray, index) → {any|undefined}

Get an item from an array by its index

.

Description:

  • Get an item from an array by its index

Example
getItemByIndex([1, 2, 3], 0) => 1

getItemByIndex([1, 2, 3], 2) => 3

getItemByIndex([1, 2, 3], -1) => 3

getItemByIndex([1, 2, 3], -2) => 2

getItemByIndex([1, 2, 3], 5) => undefined

getItemByIndex("not an array", 0) => undefined

getItemByIndex([1, 2, 3], "0") => undefined
Parameters:
Name Type Description
userArray Array

The array from which to get the item
index Number

The index of the item (supports negative indexing)
Returns:

Returns the item at the given index, or undefined if input is invalid or index is out of bounds

Type
any | undefined

(static) mapAnArray(arr, callbackopt) → {Array|undefined}

Map over an array using a callback, or return original items if no callback is provided

.

Description:

  • Map over an array using a callback, or return original items if no callback is provided

Example
mapAnArray([1, 2, 3], x => x * 2) => [2, 4, 6]

mapAnArray(["a", "b"], (item, index) => item + index) => ["a0", "b1"]

mapAnArray([1, 2, 3]) => [1, 2, 3]  // callback not provided

mapAnArray("not an array", x => x) => undefined
Parameters:
Name Type Attributes Description
arr Array

The array to map
callback function <optional>

Optional function applied to each element (receives item and index)
Returns:

Returns a new mapped array, or undefined if input is invalid

Type
Array | undefined

(static) merginMultipleArray() → {Array|undefined}

Merge multiple arrays into a single array

.

Description:

  • Merge multiple arrays into a single array

Example
merginMultipleArray([1, 2], [3, 4]) => [1, 2, 3, 4]

merginMultipleArray(["a"], ["b", "c"], ["d"]) => ["a", "b", "c", "d"]

merginMultipleArray([1], "not an array") => undefined

merginMultipleArray([], [true, false]) => [true, false]
Parameters:
Name Type Description
...arrs Array

One or more arrays to merge
Returns:

Returns a single merged array, or undefined if any input is not an array

Type
Array | undefined

(static) removeFirstItemOfAnArray(arr) → {Array|undefined}

Remove the first item from an array

.

Description:

  • Remove the first item from an array

Example
removeFirstItemOfAnArray([1, 2, 3]) => [2, 3]

removeFirstItemOfAnArray(["a", "b"]) => ["b"]

removeFirstItemOfAnArray([]) => []

removeFirstItemOfAnArray("not an array") => undefined
Parameters:
Name Type Description
arr Array

The array from which the first item will be removed
Returns:

Returns the updated array, or undefined if input is not an array

Type
Array | undefined

(static) removeLastItemOfAnArray(arr) → {Array|undefined}

Remove the last item from an array

.

Description:

  • Remove the last item from an array

Example
removeLastItemOfAnArray([1, 2, 3]) => [1, 2]

removeLastItemOfAnArray(["a", "b"]) => ["a"]

removeLastItemOfAnArray([]) => []

removeLastItemOfAnArray("not an array") => undefined
Parameters:
Name Type Description
arr Array

The array from which the last item will be removed
Returns:

Returns the updated array, or undefined if input is not an array

Type
Array | undefined

(static) sortAnArray(arr, sortByopt) → {Array|undefined}

Sort an array generically or by object key

.

Description:

  • Sort an array generically or by object key

Example
sortAnArray([3, 1, 2]) => [1, 2, 3]

sortAnArray(["b", "a", "c"]) => ["a", "b", "c"]

sortAnArray([{ age: 30 }, { age: 20 }], "age") => [{ age: 20 }, { age: 30 }]

sortAnArray("not an array") => undefined
Parameters:
Name Type Attributes Description
arr Array

The array to sort
sortBy String <optional>

Optional key to sort objects by
Returns:

Returns the sorted array, or undefined if input is invalid

Type
Array | undefined