Array Class
Provides utility methods for working with arrays. Additional array helpers can
be found in the collection
and array-extras
modules.
Y.Array(thing)
returns a native array created from thing. Depending on
thing's type, one of the following will happen:
- Arrays are returned unmodified unless a non-zero startIndex is specified.
- Array-like collections (see
Array.test()
) are converted to arrays. - For everything else, a new array is created with thing as the sole item.
Note: elements that are also collections, such as <form>
and <select>
elements, are not automatically converted to arrays. To force a conversion,
pass true
as the value of the force parameter.
Constructor
Item Index
Methods
dedupe
-
array
Dedupes an array of strings, returning an array that's guaranteed to contain only one copy of a given string.
This method differs from Array.unique()
in that it's optimized for use only
with arrays consisting entirely of strings or entirely of numbers, whereas
unique
may be used with other value types (but is slower).
Using dedupe()
with values other than strings or numbers, or with arrays
containing a mix of strings and numbers, may result in unexpected behavior.
Returns:
Copy of array containing no duplicate values.
each
-
array
-
fn
-
[thisObj]
Executes the supplied function on each item in the array. This method wraps
the native ES5 Array.forEach()
method if available.
Parameters:
Returns:
The YUI instance.
every
-
a
-
f
-
[o]
Executes the supplied function on each item in the array. Iteration stops if the supplied function does not return a truthy value.
Parameters:
Returns:
true
if every item in the array returns true
from the
supplied function, false
otherwise.
filter
-
a
-
f
-
[o]
Executes the supplied function on each item in the array. Returns a new array containing the items for which the supplied function returned a truthy value.
Parameters:
Returns:
Array of items for which the supplied function returned a truthy value (empty if it never returned a truthy value).
find
-
a
-
f
-
[o]
Executes the supplied function on each item in the array, searching for the first item that matches the supplied function.
Parameters:
Returns:
the first item that the supplied function returns true
for,
or null
if it never returns true
.
flatten
-
a
Flattens an array of nested arrays at any abitrary depth into a single, flat array.
Parameters:
-
a
ArrayArray with nested arrays to flatten.
Returns:
An array whose nested arrays have been flattened.
forEach
()
static
Alias for each()
.
grep
-
a
-
pattern
Iterates over an array, returning a new array of all the elements that match the supplied regular expression.
Parameters:
Returns:
All the items in the array that produce a match against the supplied regular expression. If no items match, an empty array is returned.
hash
-
keys
-
[values]
Returns an object using the first array as keys and the second as values. If
the second array is not provided, or if it doesn't contain the same number of
values as the first array, then true
will be used in place of the missing
values.
Parameters:
Returns:
Hash using the first array as keys and the second as values.
Example:
Y.Array.hash(['a', 'b', 'c'], ['foo', 'bar']);
// => {a: 'foo', b: 'bar', c: true}
indexOf
-
array
-
value
-
[from=0]
Returns the index of the first item in the array that's equal (using a strict
equality check) to the specified value, or -1
if the value isn't found.
This method wraps the native ES5 Array.indexOf()
method if available.
Parameters:
Returns:
Index of the item strictly equal to value, or -1
if not
found.
invoke
-
items
-
name
-
[args*]
Executes a named method on each item in an array of objects. Items in the array that do not have a function by that name will be skipped.
Parameters:
Returns:
All return values, indexed according to the item index.
Example:
Y.Array.invoke(arrayOfDrags, 'plug', Y.Plugin.DDProxy);
lastIndexOf
-
a
-
val
-
[fromIndex]
Returns the index of the last item in the array that contains the specified
value, or -1
if the value isn't found.
Parameters:
-
a
ArrayArray to search in.
-
val
AnyValue to search for.
-
[fromIndex]
Number optionalIndex at which to start searching backwards. Defaults to the array's length - 1. If negative, it will be taken as an offset from the end of the array. If the calculated index is less than 0, the array will not be searched and
-1
will be returned.
Returns:
Index of the item that contains the value, or -1
if not
found.
map
-
a
-
f
-
[o]
Executes the supplied function on each item in the array and returns a new array containing all the values returned by the supplied function.
Parameters:
Returns:
A new array containing the return value of the supplied function for each item in the original array.
Example:
// Convert an array of numbers into an array of strings.
Y.Array.map([1, 2, 3, 4], function (item) {
return '' + item;
});
// => ['1', '2', '3', '4']
numericSort
-
a
-
b
Numeric sort convenience function.
The native Array.prototype.sort()
function converts values to strings and
sorts them in lexicographic order, which is unsuitable for sorting numeric
values. Provide Array.numericSort
as a custom sort function when you want
to sort values in numeric order.
Returns:
Difference between a and b.
Example:
[42, 23, 8, 16, 4, 15].sort(Y.Array.numericSort);
// => [4, 8, 15, 16, 23, 42]
partition
-
a
-
f
-
[o]
Partitions an array into two new arrays, one with the items for which the
supplied function returns true
, and one with the items for which the function
returns false
.
Parameters:
Returns:
An object with two properties: matches
and rejects
. Each is
an array containing the items that were selected or rejected by the test
function (or an empty array if none).
reduce
-
a
-
init
-
f
-
[o]
Executes the supplied function on each item in the array, "folding" the array into a single value.
Parameters:
Returns:
Final result from iteratively applying the given function to each element in the array.
reject
-
a
-
f
-
[o]
The inverse of Array.filter()
. Executes the supplied function on each item.
Returns a new array containing the items for which the supplied function
returned false
.
Parameters:
Returns:
The items for which the supplied function returned false
.
some
-
array
-
fn
-
[thisObj]
Executes the supplied function on each item in the array. Returning a truthy value from the function will stop the processing of remaining items.
Parameters:
Returns:
true
if the function returns a truthy value on any of the
items in the array; false
otherwise.
test
-
obj
Evaluates obj to determine if it's an array, an array-like collection, or
something else. This is useful when working with the function arguments
collection and HTMLElement
collections.
Note: This implementation doesn't consider elements that are also
collections, such as <form>
and <select>
, to be array-like.
Parameters:
-
obj
ObjectObject to test.
Returns:
A number indicating the results of the test:
- 0: Neither an array nor an array-like collection.
- 1: Real array.
- 2: Array-like collection.
unique
-
array
-
[testFn]
Returns a copy of the input array with duplicate items removed.
Note: If the input array only contains strings, the Y.Array.dedupe()
method is
a much faster alternative.
Parameters:
Returns:
Copy of the input array with duplicate items removed.