array-tools

Useful functions for working with arrays

array-tools

Useful functions for working with arrays

Example

var a = require("array-tools");

Takes input and guarantees an array back. Result can be one of three things:

  • puts a single scalar in an array
  • converts array-like object (e.g. arguments) to a real array
  • converts null or to an empty array

Category: General

ParamTypeDescription
any*the input value to convert to an array

Example

> a.arrayify(null)
[]
> a.arrayify(0)
[ 0 ]
> a.arrayify([ 1, 2 ])
[ 1, 2 ]
> function f(){ return a.arrayify(arguments); }
> f(1,2,3)
[ 1, 2, 3 ]

returns true if a value, or nested object value exists in an array

Category: General

ParamTypeDescription
arrayArraythe array to search
value*the value to search for

Example

> a.exists([ 1, 2, 3 ], 2)
true
> a.exists([ { result: false }, { result: false } ], { result: true })
false
> a.exists([ { result: true }, { result: false } ], { result: true })
true
> a.exists([ { result: true }, { result: true } ], { result: true })
true

Returns the input minus the specified values.

Category: General

ParamTypeDescription
arrayArraythe input array
toRemove*a single, or array of values to omit

Example

> a.without([ 1, 2, 3 ], 2)
[ 1, 3 ]
> a.without([ 1, 2, 3 ], [ 2, 3 ])
[ 1 ]

merge two arrays into a single array of unique values

Category: General

ParamTypeDescription
array1ArrayFirst array
array2ArraySecond array
idKeystringthe unique ID property name

Example

> var array1 = [ 1, 2 ], array2 = [ 2, 3 ];
> a.union(array1, array2)
[ 1, 2, 3 ]
> var array1 = [ { id: 1 }, { id: 2 } ], array2 = [ { id: 2 }, { id: 3 } ];
> a.union(array1, array2)
[ { id: 1 }, { id: 2 }, { id: 3 } ]
> var array2 = [ { id: 2, blah: true }, { id: 3 } ]
> a.union(array1, array2)
[ { id: 1 },
  { id: 2 },
  { id: 2, blah: true },
  { id: 3 } ]
> a.union(array1, array2, "id")
[ { id: 1 }, { id: 2 }, { id: 3 } ]

Returns the initial elements which both input arrays have in common

Category: General

ParamTypeDescription
aArrayfirst array to compare
bArraysecond array to compare

Example

> a.commonSequence([1,2,3], [1,2,4])
[ 1, 2 ]

returns an array of unique values

Category: General

ParamTypeDescription
arrayArrayinput array

Example

> n = [1,6,6,7,1]
[ 1, 6, 6, 7, 1 ]
> a.unique(n)
[ 1, 6, 7 ]

splice from index until test fails

Category: General

ParamTypeDescription
arrayArraythe input array
indexnumberthe position to begin splicing from
testRegExpthe test to continue splicing while true
...elementN*the elements to add to the array

Example

> letters = ["a", "a", "b"]
[ 'a', 'a', 'b' ]
> a.spliceWhile(letters, 0, /a/, "x")
[ 'a', 'a' ]
> letters
[ 'x', 'b' ]

Removes items from array which satisfy the query. Modifies the input array, returns the extracted.

Returns: Array - the extracted items.
Category: General

ParamTypeDescription
arrayArraythe input array, modified directly
queryfunction | objectPer item in the array, if either the function returns truthy or the exists query is satisfied, the item is extracted

flatten an array of arrays into a single array

Category: General
Since: 1.4.0
Todo

  • document

Example

> numbers = [ 1, 2, [ 3, 4 ], 5 ]
> a.flatten(numbers)
[ 1, 2, 3, 4, 5 ]

Plucks the value of the specified property from each object in the input array

Category: Record sets

ParamTypeDescription
arrayOfObjectsArray.<object>the input array of objects
...propertystringthe property(s) to pluck

Example

> var data = [
    {one: 1, two: 2},
    {two: "two"},
    {one: "one", two: "zwei"},
];
> a.pluck(data, "one");
[ 1, 'one' ]
> a.pluck(data, "two");
[ 2, 'two', 'zwei' ]
> a.pluck(data, "one", "two");
[ 1, 'two', 'one' ]

return a copy of the input arrayOfObjects containing objects having only the cherry-picked properties

Category: Record sets

ParamTypeDescription
arrayOfObjectsArray.<object>the input
...propertystringthe properties to include in the result

Example

> data = [
    { one: "un", two: "deux", three: "trois" },
    { two: "two", one: "one" },
    { four: "quattro" },
    { two: "zwei" }
]
> a.pick(data, "two")
[ { two: 'deux' },
  { two: 'two' },
  { two: 'zwei' } ]

returns an array containing items from arrayOfObjects where key/value pairs from query are matched identically

Category: Record sets

ParamTypeDescription
arrayOfObjectsArray.<object>the array to search
queryqueryan object containing the key/value pairs you want to match

Example

> dudes = [{ name: "Jim", age: 8}, { name: "Clive", age: 8}, { name: "Hater", age: 9}]
[ { name: 'Jim', age: 8 },
  { name: 'Clive', age: 8 },
  { name: 'Hater', age: 9 } ]
> a.where(dudes, { age: 8})
[ { name: 'Jim', age: 8 },
  { name: 'Clive', age: 8 } ]

returns the first item from arrayOfObjects where key/value pairs from query are matched identically

Category: Record sets

ParamTypeDescription
arrayOfObjectsArray.<object>the array to search
queryobjectan object containing the key/value pairs you want to match

Example

> dudes = [{ name: "Jim", age: 8}, { name: "Clive", age: 8}, { name: "Hater", age: 9}]
[ { name: 'Jim', age: 8 },
  { name: 'Clive', age: 8 },
  { name: 'Hater', age: 9 } ]
> a.findWhere(dudes, { age: 8})
{ name: 'Jim', age: 8 }

Sort an array of objects by one or more fields

Category: Record sets
Since: 1.5.0

ParamTypeDescription
arrayOfObjectsArray.<object>input array
columnsstring | Array.<string>column name(s) to sort by
customOrderobjectspecific sort orders, per columns

Example

>  var fixture = [
    { a: 4, b: 1, c: 1},
    { a: 4, b: 3, c: 1},
    { a: 2, b: 2, c: 3},
    { a: 2, b: 2, c: 2},
    { a: 1, b: 3, c: 4},
    { a: 1, b: 1, c: 4},
    { a: 1, b: 2, c: 4},
    { a: 3, b: 3, c: 3},
    { a: 4, b: 3, c: 1}
];
> a.sortBy(fixture, ["a", "b", "c"])
[ { a: 1, b: 1, c: 4 },
  { a: 1, b: 2, c: 4 },
  { a: 1, b: 3, c: 4 },
  { a: 2, b: 2, c: 2 },
  { a: 2, b: 2, c: 3 },
  { a: 3, b: 3, c: 3 },
  { a: 4, b: 1, c: 1 },
  { a: 4, b: 3, c: 1 },
  { a: 4, b: 3, c: 1 } ]

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© 2015 Lloyd Brookes 75pound@gmail.com