Return type | Name and parameters |
---|---|
Map
|
collectEntries()
A variant of collectEntries using the identity closure as the transform. |
Map
|
collectEntries(Closure transform)
Iterates through this array transforming each item using the transform closure
and returning a map of the resulting transformed entries.
|
Map
|
collectEntries(Map collector)
A variant of collectEntries using the identity closure as the transform. |
Map
|
collectEntries(Map collector, Closure transform)
Iterates through this array transforming each item using the transform closure
and returning a map of the resulting transformed entries.
|
List
|
collectMany(Closure projection)
Projects each item from a source array to a collection and concatenates (flattens) the resulting collections into a single list. |
Number
|
count(Closure closure)
Counts the number of occurrences which satisfy the given closure from inside this array. |
Map
|
countBy(Closure closure)
Sorts all array members into groups determined by the supplied mapping closure and counts the group size. |
Object[]
|
drop(int num)
Drops the given number of elements from the head of this array if they are available. |
Object[]
|
dropRight(int num)
Drops the given number of elements from the tail of this array if they are available. |
Object[]
|
dropWhile(Closure condition)
Create a suffix of the given array by dropping as many elements as possible from the front of the original array such that calling the given closure condition evaluates to true when passed each of the dropped elements. |
Object
|
find(Closure condition)
Finds the first element in the array that matches the given closure condition. |
Collection
|
findAll()
Finds the elements of the array matching the IDENTITY Closure (i.e. matching Groovy truth). |
Collection
|
findAll(Closure condition)
Finds all elements of the array matching the given Closure condition. |
Object
|
first()
Returns the first item from the array. |
List
|
getAt(EmptyRange range)
|
List
|
getAt(IntRange range)
|
List
|
getAt(ObjectRange range)
|
List
|
getAt(Range range)
Support the range subscript operator for an Array |
List
|
getAt(Collection indices)
Select a List of items from an array using a Collection to identify the indices to be selected. |
IntRange
|
getIndices()
Returns indices of the array. |
Collection
|
grep()
Iterates over the array returning each element that matches using the IDENTITY Closure as a filter - effectively returning all elements which satisfy Groovy truth. |
Collection
|
grep(Object filter)
Iterates over the array of items and returns a collection of items that match the given filter - calling the Object#isCase(java.lang.Object)
method used by switch statements.
|
Map
|
groupBy(Closure closure)
Sorts all array members into groups determined by the supplied mapping closure. |
Object
|
head()
Returns the first item from the Object array. |
Object[]
|
init()
Returns the items from the Object array excluding the last item. |
Object
|
inject(Closure closure)
Iterates through the given array as with inject(Object[],initialValue,closure), but using the first element of the array as the initialValue, and then iterating the remaining elements of the array. |
Object
|
inject(Object initialValue, Closure closure)
Iterates through the given array, passing in the initial value to the closure along with the first item. |
Iterator
|
iterator()
Attempts to create an Iterator for the given object by first converting it to a Collection. |
Object
|
last()
Returns the last item from the array. |
Object
|
max()
Adds max() method to Object arrays. |
Object
|
max(Closure closure)
Selects the maximum value found from the Object array using the closure to determine the correct ordering. |
Object
|
max(Comparator comparator)
Selects the maximum value found from the Object array using the given comparator. |
Object
|
min()
Adds min() method to Object arrays. |
Object
|
min(Closure closure)
Selects the minimum value found from the Object array using the closure to determine the correct ordering. |
Object
|
min(Comparator comparator)
Selects the minimum value found from the Object array using the given comparator. |
Object[]
|
minus(Iterable removeMe)
Create an array composed of the elements of the first array minus the elements of the given Iterable. |
Object[]
|
minus(Object removeMe)
Create a new object array composed of the elements of the first array minus the element to remove. |
Object[]
|
minus(Object[] removeMe)
Create an array composed of the elements of the first array minus the elements of the given array. |
Object[]
|
plus(Iterable right)
Create an array containing elements from an original array plus those from an Iterable. |
Object[]
|
plus(Object right)
Create an array containing elements from an original array plus an additional appended element. |
Object[]
|
plus(Object[] right)
Create an array as a union of two arrays. |
Object[]
|
plus(Collection right)
Create an array containing elements from an original array plus those from a Collection. |
Object[]
|
reverse()
Creates a new array containing items which are the same as this array but in reverse order. |
Object[]
|
reverse(boolean mutate)
Reverse the items in an array. |
Object[]
|
reverseEach(Closure closure)
Iterate over each element of the array in the reverse order. |
Object[]
|
sort()
Modifies this array so that its elements are in sorted order. |
Object[]
|
sort(boolean mutate)
Sorts the given array into sorted order. |
Object[]
|
sort(boolean mutate, Closure closure)
Modifies this array so that its elements are in sorted order using the Closure to determine the correct ordering. |
Object[]
|
sort(boolean mutate, Comparator comparator)
Modifies this array so that its elements are in sorted order as determined by the given comparator. |
Object[]
|
sort(Closure closure)
Sorts the elements from this array into a newly created array using the Closure to determine the correct ordering. |
Object[]
|
sort(Comparator comparator)
Sorts the given array into sorted order using the given comparator. |
Object[]
|
swap(int i, int j)
Swaps two elements at the specified positions. |
Object[]
|
tail()
Returns the items from the array excluding the first item. |
Object[]
|
take(int num)
Returns the first num elements from the head of this array.
|
Object[]
|
takeRight(int num)
Returns the last num elements from the tail of this array.
|
Object[]
|
takeWhile(Closure condition)
Returns the longest prefix of this array where each element passed to the given closure evaluates to true. |
List
|
toList()
Allows conversion of arrays into a mutable List. |
Object[]
|
toSorted()
Returns a sorted version of the given array using the supplied comparator. |
Object[]
|
toSorted(Closure condition)
Sorts the elements from this array into a newly created array using the Closure to determine the correct ordering. |
Object[]
|
toSorted(Comparator comparator)
Returns a sorted version of the given array using the supplied comparator to determine the resulting order. |
Object[]
|
toUnique()
Returns a new Array containing the items from the original Array but with duplicates removed using the natural ordering of the items in the array. |
Object[]
|
toUnique(Closure condition)
Returns a new Array containing the items from the original Array but with duplicates removed with the supplied comparator determining which items are unique. |
Object[]
|
toUnique(Comparator comparator)
Returns a new Array containing the items from the original Array but with duplicates removed with the supplied comparator determining which items are unique. |
A variant of collectEntries using the identity closure as the transform.
Iterates through this array transforming each item using the transform
closure
and returning a map of the resulting transformed entries.
def letters = "abc" def nums = [0, 1, 2] as Integer[] // collect letters with index using list style assert nums.collectEntries { index -> [index, letters[index]] } == [0:'a', 1:'b', 2:'c'] // collect letters with index using map style assert nums.collectEntries { index -> [(index): letters[index]] } == [0:'a', 1:'b', 2:'c']Note: When using the list-style of result, the behavior is '
def (key, value) = listResultFromClosure
'.
While we strongly discourage using a list of size other than 2, Groovy's normal semantics apply in this case;
throwing away elements after the second one and using null for the key or value for the case of a shortened list.
transform
- the closure used for transforming, which has an item from self as the parameter and
should return a Map.Entry, a Map or a two-element list containing the resulting key and valueA variant of collectEntries using the identity closure as the transform.
collector
- the Map into which the transformed entries are putIterates through this array transforming each item using the transform
closure
and returning a map of the resulting transformed entries.
def letters = "abc" def nums = [0, 1, 2] as Integer[] // collect letters with index assert nums.collectEntries( [:] ) { index -> [index, letters[index]] } == [0:'a', 1:'b', 2:'c'] assert nums.collectEntries( [4:'d'] ) { index -> [(index+1): letters[index]] } == [1:'a', 2:'b', 3:'c', 4:'d']Note: When using the list-style of result, the behavior is '
def (key, value) = listResultFromClosure
'.
While we strongly discourage using a list of size other than 2, Groovy's normal semantics apply in this case;
throwing away elements after the second one and using null for the key or value for the case of a shortened list.
If your collector Map doesn't support null keys or values, you might get a runtime error, e.g. NullPointerException or IllegalArgumentException.
collector
- the Map into which the transformed entries are puttransform
- the closure used for transforming, which has an item from self as the parameter and
should return a Map.Entry, a Map or a two-element list containing the resulting key and valueProjects each item from a source array to a collection and concatenates (flattens) the resulting collections into a single list.
def nums = [1, 2, 3, 4, 5, 6] as Object[] def squaresAndCubesOfEvens = nums.collectMany{ it % 2 ? [] : [it**2, it**3] } assert squaresAndCubesOfEvens == [4, 8, 16, 64, 36, 216]
projection
- a projecting Closure returning a collection of itemsCounts the number of occurrences which satisfy the given closure from inside this array.
closure
- a closure conditionSorts all array members into groups determined by the supplied mapping closure and counts the group size. The closure should return the key that each item should be grouped by. The returned Map will have an entry for each distinct key returned from the closure, with each value being the frequency of items occurring for that group.
Example usage:
assert ([1,2,2,2,3] as Object[]).countBy{ it % 2 } == [1:2, 0:3]
closure
- a closure mapping items to the frequency keysDrops the given number of elements from the head of this array if they are available.
String[] strings = [ 'a', 'b', 'c' ] assert strings.drop( 0 ) == [ 'a', 'b', 'c' ] as String[] assert strings.drop( 2 ) == [ 'c' ] as String[] assert strings.drop( 5 ) == [] as String[]
num
- the number of elements to drop from this arraynum
ones, or else the empty array, if this
array has less than num
elements.Drops the given number of elements from the tail of this array if they are available.
String[] strings = [ 'a', 'b', 'c' ] assert strings.dropRight( 0 ) == [ 'a', 'b', 'c' ] as String[] assert strings.dropRight( 2 ) == [ 'a' ] as String[] assert strings.dropRight( 5 ) == [] as String[]
num
- the number of elements to drop from this arraynum
ones, or else the empty array, if this
array has less than num
elements.Create a suffix of the given array by dropping as many elements as possible from the front of the original array such that calling the given closure condition evaluates to true when passed each of the dropped elements.
def nums = [ 1, 3, 2 ] as Integer[] assert nums.dropWhile{ it <= 3 } == [ ] as Integer[] assert nums.dropWhile{ it < 3 } == [ 3, 2 ] as Integer[] assert nums.dropWhile{ it != 2 } == [ 2 ] as Integer[] assert nums.dropWhile{ it == 0 } == [ 1, 3, 2 ] as Integer[]
condition
- the closure that must evaluate to true to
continue dropping elementsFinds the first element in the array that matches the given closure condition. Example:
def list = [1,2,3] as Integer[] assert 2 == list.find { it > 1 } assert null == list.find { it > 5 }
condition
- a closure conditionFinds the elements of the array matching the IDENTITY Closure (i.e. matching Groovy truth).
Example:
def items = [1, 2, 0, false, true, '', 'foo', [], [4, 5], null] as Object[] assert items.findAll() == [1, 2, true, 'foo', [4, 5]]
Finds all elements of the array matching the given Closure condition.
def items = [1,2,3,4] as Integer[] assert [2,4] == items.findAll { it % 2 == 0 }
condition
- a closure conditionReturns the first item from the array.
def array = [3, 4, 2].toArray() assert array.first() == 3
range
- an EmptyRangerange
- an IntRangerange
- an ObjectRangeSupport the range subscript operator for an Array
range
- a RangeSelect a List of items from an array using a Collection to identify the indices to be selected.
indices
- a Collection of indicesReturns indices of the array.
Example:
String[] letters = ['a', 'b', 'c', 'd'] assert 0..<4 == letters.indices
Iterates over the array returning each element that matches using the IDENTITY Closure as a filter - effectively returning all elements which satisfy Groovy truth.
Example:
def items = [1, 2, 0, false, true, '', 'foo', [], [4, 5], null] as Object[] assert items.grep() == [1, 2, true, 'foo', [4, 5]]
Iterates over the array of items and returns a collection of items that match
the given filter - calling the Object#isCase(java.lang.Object)
method used by switch statements. This method can be used with different
kinds of filters like regular expressions, classes, ranges etc.
Example:
def items = ['a', 'b', 'aa', 'bc', 3, 4.5] as Object[] assert items.grep( ~/a+/ ) == ['a', 'aa'] assert items.grep( ~/../ ) == ['aa', 'bc'] assert items.grep( Number ) == [ 3, 4.5 ] assert items.grep{ it.toString().size() == 1 } == [ 'a', 'b', 3 ]
filter
- the filter to perform on each element of the array (using the Object#isCase(java.lang.Object) method)Sorts all array members into groups determined by the supplied mapping closure. The closure should return the key that this item should be grouped by. The returned LinkedHashMap will have an entry for each distinct key returned from the closure, with each value being a list of items for that group.
Example usage:
Integer[] items = [1,2,3,4,5,6] assert [0:[2,4,6], 1:[1,3,5]] == items.groupBy { it % 2 }
closure
- a closure mapping entries on keysReturns the first item from the Object array.
def array = [3, 4, 2].toArray() assert array.head() == 3
Returns the items from the Object array excluding the last item.
String[] strings = ["a", "b", "c"] def result = strings.init() assert result.length == 2 assert strings.class.componentType == String
Iterates through the given array as with inject(Object[],initialValue,closure), but using the first element of the array as the initialValue, and then iterating the remaining elements of the array.
closure
- a closureIterates through the given array, passing in the initial value to the closure along with the first item. The result is passed back (injected) into the closure along with the second item. The new result is injected back into the closure along with the third item and so on until all elements of the array have been used. Also known as foldLeft in functional parlance.
initialValue
- some initial valueclosure
- a closureAttempts to create an Iterator for the given object by first converting it to a Collection.
Returns the last item from the array.
def array = [3, 4, 2].toArray() assert array.last() == 2
Adds max() method to Object arrays.
Selects the maximum value found from the Object array using the closure to determine the correct ordering.
If the closure has two parameters it is used like a traditional Comparator. I.e. it should compare its two parameters for order, returning a negative integer, zero, or a positive integer when the first parameter is less than, equal to, or greater than the second respectively. Otherwise, the Closure is assumed to take a single parameter and return a Comparable (typically an Integer) which is then used for further comparison.
closure
- a Closure used to determine the correct orderingSelects the maximum value found from the Object array using the given comparator.
comparator
- a ComparatorAdds min() method to Object arrays.
Selects the minimum value found from the Object array using the closure to determine the correct ordering.
If the closure has two parameters it is used like a traditional Comparator. I.e. it should compare its two parameters for order, returning a negative integer, zero, or a positive integer when the first parameter is less than, equal to, or greater than the second respectively. Otherwise, the Closure is assumed to take a single parameter and return a Comparable (typically an Integer) which is then used for further comparison.
closure
- a Closure used to determine the correct orderingSelects the minimum value found from the Object array using the given comparator.
comparator
- a ComparatorCreate an array composed of the elements of the first array minus the elements of the given Iterable.
removeMe
- a Collection of elements to removeCreate a new object array composed of the elements of the first array minus the element to remove.
removeMe
- an element to remove from the arrayCreate an array composed of the elements of the first array minus the elements of the given array.
removeMe
- an array of elements to removeCreate an array containing elements from an original array plus those from an Iterable.
class AbcIterable implements Iterable{ Iterator iterator() { "abc".iterator() } } String[] letters = ['x', 'y', 'z'] def result = letters + new AbcIterable() assert result == ['x', 'y', 'z', 'a', 'b', 'c'] as String[] assert result.class.array
right
- an Iterable to be appendedCreate an array containing elements from an original array plus an additional appended element.
Integer[] a = [1, 2, 3] Integer[] result = a + 4 assert result == [1, 2, 3, 4] as Integer[]
right
- the value to appendCreate an array as a union of two arrays.
Integer[] a = [1, 2, 3] Integer[] b = [4, 5, 6] assert a + b == [1, 2, 3, 4, 5, 6] as Integer[]
right
- the right ArrayCreate an array containing elements from an original array plus those from a Collection.
Integer[] a = [1, 2, 3] def additions = [7, 8] assert a + additions == [1, 2, 3, 7, 8] as Integer[]
right
- a Collection to be appendedCreates a new array containing items which are the same as this array but in reverse order.
Reverse the items in an array. If mutate is true, the original array is modified in place and returned. Otherwise, a new array containing the reversed items is produced.
mutate
- true if the array itself should be reversed in place and returned, false if a new array should be createdIterate over each element of the array in the reverse order.
closure
- a closure to which each item is passedModifies this array so that its elements are in sorted order. The array items are assumed to be comparable.
Sorts the given array into sorted order. The array items are assumed to be comparable. If mutate is true, the array is sorted in place and returned. Otherwise, a new sorted array is returned and the original array remains unchanged.
def orig = ["hello","hi","Hey"] as String[] def sorted = orig.sort(false) assert orig == ["hello","hi","Hey"] as String[] assert sorted == ["Hey","hello","hi"] as String[] orig.sort(true) assert orig == ["Hey","hello","hi"] as String[]
mutate
- false will always cause a new array to be created, true will mutate the array in placeModifies this array so that its elements are in sorted order using the Closure to determine the correct ordering. If mutate is false, a new array is returned and the original array remains unchanged. Otherwise, the original array is sorted in place and returned.
If the closure has two parameters it is used like a traditional Comparator. I.e. it should compare its two parameters for order, returning a negative integer, zero, or a positive integer when the first parameter is less than, equal to, or greater than the second respectively. Otherwise, the Closure is assumed to take a single parameter and return a Comparable (typically an Integer) which is then used for further comparison.
def orig = ["hello","hi","Hey"] as String[] def sorted = orig.sort(false) { it.size() } assert orig == ["hello","hi","Hey"] as String[] assert sorted == ["hi","Hey","hello"] as String[] orig.sort(true) { it.size() } assert orig == ["hi","Hey","hello"] as String[]
mutate
- false will always cause a new array to be created, true will mutate arrays in placeclosure
- a Closure used to determine the correct orderingModifies this array so that its elements are in sorted order as determined by the given comparator. If mutate is true, the array is sorted in place and returned. Otherwise, a new sorted array is returned and the original array remains unchanged.
def orig = ["hello","hi","Hey"] as String[] def sorted = orig.sort(false, String.CASE_INSENSITIVE_ORDER) assert orig == ["hello","hi","Hey"] as String[] assert sorted == ["hello","Hey","hi"] as String[] orig.sort(true, String.CASE_INSENSITIVE_ORDER) assert orig == ["hello","Hey","hi"] as String[]
mutate
- false will always cause a new array to be created, true will mutate arrays in placecomparator
- a Comparator used for the comparisonSorts the elements from this array into a newly created array using the Closure to determine the correct ordering.
If the closure has two parameters it is used like a traditional Comparator. I.e. it should compare its two parameters for order, returning a negative integer, zero, or a positive integer when the first parameter is less than, equal to, or greater than the second respectively. Otherwise, the Closure is assumed to take a single parameter and return a Comparable (typically an Integer) which is then used for further comparison.
closure
- a Closure used to determine the correct orderingSorts the given array into sorted order using the given comparator.
comparator
- a Comparator used for the comparisonSwaps two elements at the specified positions.
Example:
assert (["a", "c", "b", "d"] as String[]) == (["a", "b", "c", "d"] as String[]).swap(1, 2)
i
- a positionj
- a positionReturns the items from the array excluding the first item.
String[] strings = ["a", "b", "c"] def result = strings.tail() assert result.class.componentType == String String[] expected = ["b", "c"] assert result == expected
Returns the first num
elements from the head of this array.
String[] strings = [ 'a', 'b', 'c' ] assert strings.take( 0 ) == [] as String[] assert strings.take( 2 ) == [ 'a', 'b' ] as String[] assert strings.take( 5 ) == [ 'a', 'b', 'c' ] as String[]
num
- the number of elements to take from this arraynum
elements of this array,
or else the whole array if it has less then num
elements.Returns the last num
elements from the tail of this array.
String[] strings = [ 'a', 'b', 'c' ] assert strings.takeRight( 0 ) == [] as String[] assert strings.takeRight( 2 ) == [ 'b', 'c' ] as String[] assert strings.takeRight( 5 ) == [ 'a', 'b', 'c' ] as String[]
num
- the number of elements to take from this arraynum
elements of this array,
or else the whole array if it has less then num
elements.Returns the longest prefix of this array where each element passed to the given closure evaluates to true.
def nums = [ 1, 3, 2 ] as Integer[] assert nums.takeWhile{ it < 1 } == [] as Integer[] assert nums.takeWhile{ it < 3 } == [ 1 ] as Integer[] assert nums.takeWhile{ it < 4 } == [ 1, 3, 2 ] as Integer[]
condition
- the closure that must evaluate to true to
continue taking elementsAllows conversion of arrays into a mutable List.
Returns a sorted version of the given array using the supplied comparator.
Sorts the elements from this array into a newly created array using the Closure to determine the correct ordering.
If the closure has two parameters it is used like a traditional Comparator. I.e. it should compare its two parameters for order, returning a negative integer, zero, or a positive integer when the first parameter is less than, equal to, or greater than the second respectively. Otherwise, the Closure is assumed to take a single parameter and return a Comparable (typically an Integer) which is then used for further comparison.
condition
- a Closure used to determine the correct orderingReturns a sorted version of the given array using the supplied comparator to determine the resulting order.
def sumDigitsComparator = [compare: { num1, num2 -> num1.toString().toList()*.toInteger().sum() <=> num2.toString().toList()*.toInteger().sum() }] as Comparator Integer[] nums = [9, 44, 222, 7000] def result = nums.toSorted(sumDigitsComparator) assert result instanceof Integer[] assert result == [222, 7000, 44, 9]
comparator
- a Comparator used for the comparisonReturns a new Array containing the items from the original Array but with duplicates removed using the natural ordering of the items in the array.
String[] letters = ['c', 'a', 't', 's', 'a', 't', 'h', 'a', 't'] String[] expected = ['c', 'a', 't', 's', 'h'] def result = letters.toUnique() assert result == expected assert result.class.componentType == String
Returns a new Array containing the items from the original Array but with duplicates removed with the supplied comparator determining which items are unique.
String[] letters = ['c', 'a', 't', 's', 'A', 't', 'h', 'a', 'T'] String[] expected = ['c', 'a', 't', 's', 'h'] assert letters.toUnique{ p1, p2 -> p1.toLowerCase() <=> p2.toLowerCase() } == expected assert letters.toUnique{ it.toLowerCase() } == expected
condition
- a Closure used to determine unique itemsReturns a new Array containing the items from the original Array but with duplicates removed with the supplied comparator determining which items are unique.
String[] letters = ['c', 'a', 't', 's', 'A', 't', 'h', 'a', 'T'] String[] lower = ['c', 'a', 't', 's', 'h'] class LowerComparator implements Comparator { int compare(let1, let2) { let1.toLowerCase() <=> let2.toLowerCase() } } assert letters.toUnique(new LowerComparator()) == lower
comparator
- a Comparator used to determine unique (equal) items
If null
, the Comparable natural ordering of the elements will be used.