xdash / default
Variable: default
default:
Object
Type declaration
noop
noop: () =>
void
Empty function.
Returns
void
and()
AND operator for functions.
Type parameters
• Args extends readonly unknown[]
Parameters
• …fns: (…args) => boolean[]
functions to combine
Returns
Function
a function that returns true if all of the input functions return true
Parameters
• …args:
ArgsReturns
boolean
Example
const isEven = (n: number) => n % 2 === 0
const isPositive = (n: number) => n > 0
const isPositiveEven = and(isEven, isPositive)
isPositiveEven(2) // returns true
asError()
Converts a value to an error.
Parameters
• value: unknown
value to convert
Returns
Error
the value as an error
camelCase()
Converts a string to camelCase
Parameters
• str: string
string to convert
Returns
string
the string in camelCase
Example
camelCase('foo-bar') // returns 'fooBar'
camelCase('foo_bar') // returns 'fooBar'
camelCase('FooBar') // returns 'fooBar'
camelCase('FOO_BAR') // returns 'fooBar'
capitalize()
Capitalizes the first letter of a string
Parameters
• str: string
string to capitalize
Returns
string
the string with the first letter capitalized
Example
capitalize('foo') // returns 'Foo'
capitalize('FOO') // returns 'FOO'
capitalize('123') // returns '123'
capitalize('') // returns ''
chunk()
Creates an array of elements split into groups the length of size. If array can’t be split evenly, the final chunk will be the remaining elements.
Type parameters
• T
Parameters
• arr: T[]
• size: number
Returns
T[][]
compact()
Compacts an array by removing null and undefined values.
Type parameters
• T
Parameters
• arr: (undefined | null | false | 0 | T)[]
array to compact
Returns
T[]
the compacted array
concat()
Concatenates arrays
Type parameters
• T
Parameters
• …arrs: T[][]
arrays to concatenate
Returns
T[]
the concatenated array
detectCase()
Detects the case of a string
Parameters
• str: string
string to detect the case of
Returns
"camel" | "kebab" | "screaming-kebab" | "snake" | "screaming-snake" | "pascal" | "lower" | "upper" | "mixed" | "none"
the detected case of the string
Example
detectCase('fooBar') // returns 'camel'
detectCase('foo-bar') // returns 'kebab'
detectCase('FOO-BAR') // returns 'screaming-kebab'
detectCase('foo_bar') // returns 'snake'
detectCase('FOO_BAR') // returns 'screaming-snake'
detectCase('FooBar') // returns 'pascal'
detectCase('FOO BAR') // returns 'upper'
detectCase('foo bar') // returns 'lower'
detectCase('fooBar-baz') // returns 'mixed
detectCase('foo BAR') // returns 'mixed
detectCase('') // returns 'none'
difference()
Creates an array of unique values that are included in the first provided array, but not in the second.
Type parameters
• T
Parameters
• arr: T[]
array to difference from
• values: T[]
values to exclude
Returns
T[]
the differenced array
ensure()
ensure(checkFn, errorMsg)
Determines if a value is a number.
Type parameters
• T
• Args extends readonly unknown[] = []
Parameters
• checkFn
function to check the value
• errorMsg?: string
error message to throw if the value does not match the expected type
Returns
Function
a function that checks if a value matches the expected type
Parameters
• value:
unknown• …args:
ArgsReturns
T
Example
const ensureArr = ensure(isArr, 'Value is not an array')
const arr = ensureArr(123) // throws an error
const arr2 = ensureArr([1, 2, 3]) // returns [1, 2, 3]
ensure(checkFn, errorMsg)
Type parameters
• T
• Args extends readonly unknown[] = []
Parameters
• checkFn
• errorMsg?: string
Returns
Function
Parameters
• value:
T• …args:
ArgsReturns
T
entries()
Gets the entries of an object.
Type parameters
• T extends object
Parameters
• obj: T
object to check
Returns
[keyof T, T[keyof T]][]
true if the value is a number, false otherwise
fillKeys()
Fills an array with a value.
Type parameters
• T extends PropertyKey
• V
Parameters
• keys: T[]
keys to fill
• value: V
value to fill the keys with
Returns
Record<T, V>
an object with the keys filled with the value
filter()
Removes elements from an array for which the callback returns false.
Type parameters
• T
Parameters
• arr: T[]
array to filter
• fn
callback to filter the array
Returns
T[]
the filtered array
first()
Returns the first element of an array
Type parameters
• T
Parameters
• arr: T[]
array to get the first element from
Returns
T
the first element of the array
hasOwn()
Determines if an object has a key.
Parameters
• obj: Record<any, any>
object to check
• key: PropertyKey
key to check
• param2= {}
options to customize the check
• param2.ignoreCase?: boolean= false
Returns
key is any
true if the object has the key, false otherwise
intersection()
Creates an array of unique values that are included in all given arrays using SameValueZero for equality comparisons.
Type parameters
• T
Parameters
• …arrs: T[][]
arrays to intersect
Returns
T[]
the intersected array
isArr()
Determines if a value is an array.
Parameters
• value: unknown
value to check
Returns
value is any[]
true if the value is an array, false otherwise
isEmpty()
Determines if a value is empty.
Parameters
• value: any
Returns
boolean
isFn()
Determines if a value is a function.
Parameters
• value: unknown
value to check
Returns
value is Function
true if the value is a function, false otherwise
isKeyOf()
Determines if a value is a key of an object.
Type parameters
• T extends object
Parameters
• value: unknown
value to check
• obj: T
object to check if the value is a key of
Returns
value is keyof T
true if the value is a key of the object, false otherwise
isNullish()
Determines if a value is null or undefined.
Parameters
• value: unknown
value to check
Returns
value is undefined | null
true if the value is a number, false otherwise
isNum()
Determines if a value is a number.
Parameters
• value: unknown
value to check
Returns
value is number
true if the value is a number, false otherwise
isObj()
Determines if a value is an object.
Parameters
• value: unknown
value to check
Returns
value is object
true if the value is an object, false otherwise
isPromise()
Determines if a value is a promise.
Parameters
• value: unknown
value to check
Returns
value is Promise<unknown>
true if the value is a promise, false otherwise
isStr()
Determines if a value is a string.
Parameters
• value: unknown
value to check
Returns
value is string
true if the value is a string, false otherwise
kebabCase()
Converts a string to kebab-case
Parameters
• str: string
string to convert
• options= undefined
options for the conversion
• options.screaming: boolean= false
Returns
string
the string in kebab-case
Example
kebabCase('fooBar') // returns 'foo-bar'
kebabCase('foo_bar') // returns 'foo-bar'
kebabCase('foo-bar') // returns 'foo-bar'
kebabCase('FOO_BAR') // returns 'foo-bar'
kebabCase('foo') // returns 'foo'
kebabCase('') // returns ''
kebabCase('fooBar', { screaming: true }) // returns 'FOO-BAR'
kebabCase('foo_bar', { screaming: true }) // returns 'FOO-BAR'
kebabCase('foo-bar', { screaming: true }) // returns 'FOO-BAR'
kebabCase('FOO_BAR', { screaming: true }) // returns 'FOO-BAR'
kebabCase('foo', { screaming: true }) // returns 'FOO'
keys()
Gets the keys of an object.
Type parameters
• T extends object
Parameters
• obj: T
object to check
Returns
keyof T[]
true if the value is a number, false otherwise
last()
Returns the last element of an array
Type parameters
• T
Parameters
• arr: T[]
array to get the last element from
Returns
T
the last element of the array
lowerCase()
Converts a string to lower case
Parameters
• str: string
string to convert
Returns
string
the string in lower case
Example
lowerCase('FOO') // returns 'foo'
lowerCase('foo') // returns 'foo'
lowerCase('123') // returns '123'
lowerCase('') // returns ''
map()
Maps an array of values to an array of results of the callback.
Type parameters
• T
• U
Parameters
• arr: T[]
array to map
• fn
callback to map the array
Returns
U[]
the mapped array
not()
NOT operator for functions.
Type parameters
• Args extends readonly unknown[]
Parameters
• fn
function to negate
Returns
Function
a function that negates the result of the input function
Parameters
• …args:
ArgsReturns
boolean
Example
const isEven = (n: number) => n % 2 === 0
const isOdd = not(isEven)
isOdd(2) // returns false
or()
OR operator for functions.
Type parameters
• Args extends readonly unknown[]
Parameters
• …fns: (…args) => boolean[]
functions to combine
Returns
Function
a function that returns true if any of the input functions return true
Parameters
• …args:
ArgsReturns
boolean
Example
const isEven = (n: number) => n % 2 === 0
const isPositive = (n: number) => n > 0
const isPositiveOrEven = or(isEven, isPositive)
isPositiveOrEven(2) // returns true
isPositiveOrEven(3) // returns true
pascalCase()
Converts a string to PascalCase
Parameters
• str: string
string to convert
Returns
string
the string in PascalCase
Example
pascalCase('fooBar') // returns 'FooBar'
pascalCase('foo-bar') // returns 'FooBar'
pascalCase('foo_bar') // returns 'FooBar'
pascalCase('FOO_BAR') // returns 'FooBar'
pascalCase('foo') // returns 'Foo'
pascalCase('') // returns ''
reduce()
Reduces an array to a value which is the accumulated result of running each element in the array through the callback.
Type parameters
• T
• U
Parameters
• arr: T[]
array to reduce
• fn
callback to reduce the array
• initial: U
initial value
Returns
U
the reduced value
separateWords()
Separates words in a string based on the detected case.
Parameters
• str: string
The string to separate.
Returns
string[]
An array of separated words.
Example
separateWords('fooBar') // returns ['foo', 'Bar']
separateWords('foo-bar') // returns ['foo', 'bar']
separateWords('FOO_BAR') // returns ['FOO', 'BAR']
separateWords('foo bar') // returns ['foo', 'bar']
separateWords('') // returns []
separateWords('fooBar-baz') // returns ['foo', 'Bar', 'baz']
snakeCase()
Converts a string to snake_case
Parameters
• str: string
string to convert
• options= undefined
options for the conversion
• options.screaming: boolean= false
Returns
string
the string in snake_case
Example
snakeCase('fooBar') // returns 'foo_bar'
snakeCase('foo-bar') // returns 'foo_bar'
snakeCase('foo_bar') // returns 'foo_bar'
snakeCase('FOO_BAR') // returns 'foo_bar'
snakeCase('foo') // returns 'foo'
snakeCase('') // returns ''
snakeCase('fooBar', { screaming: true }) // returns 'FOO_BAR'
snakeCase('foo-bar', { screaming: true }) // returns 'FOO_BAR'
snakeCase('foo_bar', { screaming: true }) // returns 'FOO_BAR'
snakeCase('FOO_BAR', { screaming: true }) // returns 'FOO_BAR'
snakeCase('foo', { screaming: true }) // returns 'FOO'
snakeCase('fooBar', { screaming: true }) // returns 'FOO_BAR'
snakeCase('foo-bar', { screaming: true }) // returns 'FOO_BAR'
split()
Splits a string into an array of substrings based on a separator
Parameters
• str: string
string to split
• separator: string | RegExp
separator to split the string by
• limit?: number
maximum number of substrings to return
Returns
string[]
an array of substrings
take()
Returns the first n elements of an array
Type parameters
• T
Parameters
• arr: T[]
array to get the first n elements from
• n: number
number of elements to get
Returns
T[]
the first n elements of the array
takeRight()
Returns the last n elements of an array
Type parameters
• T
Parameters
• arr: T[]
• size: number
Returns
T[]
throwError()
Throws an error with the given message.
Parameters
• message: string= ''
error message
Returns
never
toEnum()
Converts a list of strings to an enum.
Type parameters
• T extends readonly string[]
• CapitalizeKeys extends boolean = true
• CapitalizeValues extends boolean = false
Parameters
• list: T
list of strings to convert to an enum
• options= {}
options to customize the enum
• options.capitalizeKeys?: CapitalizeKeys
• options.capitalizeValues?: CapitalizeValues
Returns
EnumFromList<T, CapitalizeKeys, CapitalizeValues>
an enum from the list
toObj()
Converts an array to an object.
Type parameters
• T
• R = T
Parameters
• arr: T[]
array to fill
• keyFn
function to get the key from the item
• valueFn= undefined
function to get the value from the item
Returns
Record<PropertyKey, R>
an object with the keys and values from the array
union()
Creates an array of unique values, in order, from all given arrays using SameValueZero for equality comparisons.
Type parameters
• T
Parameters
• …arrs: T[][]
arrays to union
Returns
T[]
the unioned array
uniq()
Unique values from an array. Order is not guaranteed.
Type parameters
• T
Parameters
• arr: T[]
array to get unique values from
Returns
T[]
the array with unique values
uniqBy()
Unique values from an array, based on a comparator function.
Type parameters
• T
Parameters
• arr: T[]
array to get unique values from
• fn
comparator function
Returns
T[]
the array with unique values
upperCase()
Converts a string to upper case
Parameters
• str: string
string to convert
Returns
string
the string in upper case
Example
upperCase('foo') // returns 'FOO'
upperCase('FOO') // returns 'FOO'
upperCase('123') // returns '123'
upperCase('') // returns ''
upperCase('foo-bar') // returns 'FOO-BAR'
values()
Gets the values of an object.
Type parameters
• T extends object
Parameters
• obj: T
object to check
Returns
T[keyof T][]
true if the value is a number, false otherwise
xor()
XOR operator for functions.
Type parameters
• Args extends readonly unknown[]
Parameters
• …fns: (…args) => boolean[]
functions to combine
Returns
Function
a function that returns true if exactly one of the input functions returns true
Parameters
• …args:
ArgsReturns
boolean
Example
const isEven = (n: number) => n % 2 === 0
const isPositive = (n: number) => n > 0
const isPositiveXorEven = xor(isEven, isPositive)
isPositiveXorEven(2) // returns false
isPositiveXorEven(3) // returns true
isPositiveXorEven(4) // returns false