Functions -
lang.array
| enumerate |
Returns a new array consisting of index and member pairs. |
| filter |
Selects the members from an array for which a function returns true. |
| forEach |
Applies a function to each member of an array. |
| fromBase16 |
Returns the byte array that a string represents in Base16. |
| fromBase64 |
Returns the byte array that a string represents in Base64. |
| indexOf |
Returns the index of first member of |
| iterator |
Returns an iterator over an array. |
| lastIndexOf |
Returns the index of last member of |
| length |
Returns the number of members of an array. |
| map |
Applies a function to each member of an array and returns an array of the results. |
| pop |
Removes and returns the last member of an array. |
| push |
Adds values to the end of an array. |
| reduce |
Combines the members of an array using a combining function. |
| remove |
Removes a member of an array. |
| removeAll |
Removes all members of an array. |
| reverse |
Reverses the order of the members of an array. |
| setLength |
Changes the length of an array. |
| shift |
Removes and returns first member of an array. |
| slice |
Returns a subarray starting from |
| sort |
Sorts an array using a comparator function. |
| toBase16 |
Returns the string that is the Base16 representation of an array of bytes. |
| toBase64 |
Returns the string that is the Base64 representation of an array of bytes. |
| toStream |
Returns a stream from the given array. |
| unshift |
Adds values to the start of an array. |
enumerate
(Type[] arr)
returns [int, Type][]Returns a new array consisting of index and member pairs.
Parameters
- arr Type[]
-
the array
-
Return Type
([int, Type][]) array of index, member pairs
filter
(Type[] arr, function(Type) returns (boolean) func)
Selects the members from an array for which a function returns true.
Parameters
- arr Type[]
-
the array
-
func
function(Type) returns (boolean) -
a predicate to apply to each member to test whether it should be selected
-
Return Type
(Type[]) new array only containing members of
arrfor whichfuncevaluates to true
forEach
(Type[] arr, function(Type) returns (()) func)
Applies a function to each member of an array.
The parameter func is applied to each member of array arr in order.
Parameters
- arr Type[]
-
the array
-
func
function(Type) returns (()) -
a function to apply to each member
fromBase16
(string str)
returns byte[] | errorReturns the byte array that a string represents in Base16.
str must consist of the characters 0..9, A..F, a..f
and whitespace as allowed by a Ballerina Base16Literal.
Parameters
- str string
-
Base16 string representation
-
Return Type
(byte[] | error) the byte array or error
fromBase64
(string str)
returns byte[] | errorReturns the byte array that a string represents in Base64.
str must consist of the characters A..Z, a..z, 0..9, +, /, =
and whitespace as allowed by a Ballerina Base64Literal.
Parameters
- str string
-
Base64 string representation
-
Return Type
(byte[] | error) the byte array or error
indexOf
(PureType[] arr, PureType val, int startIndex)
returns int?Returns the index of first member of arr that is equal to val if there is one.
Returns () if not found.
Equality is tested using ==.
Parameters
- arr PureType[]
-
the array
- val PureType
-
member to search for
- startIndex int (default 0)
-
index to start the search from
-
Return Type
(int?) index of the member if found, else
()
iterator
(Type[] arr)
returns object { public function next () returns (record {| (any|error) value; |}?); }Returns an iterator over an array.
Parameters
- arr Type[]
-
the array
-
Return Type
(object { public function next () returns (record {| (any|error) value; |}?); }) a new iterator object that will iterate over the members of
arr.
lastIndexOf
(PureType[] arr, PureType val, int startIndex)
returns int?Returns the index of last member of arr that is equal to val if there is one.
Returns () if not found.
Equality is tested using ==.
Parameters
- arr PureType[]
-
the array
- val PureType
-
member to search for
- startIndex int (default arr.length(arr) - 1)
-
index to start searching backwards from
-
Return Type
(int?) index of the member if found, else
()
length
(any | error[] arr)
returns intReturns the number of members of an array.
Parameters
- arr any | error[]
-
the array
-
Return Type
(int) number of members in
arr
map
(Type[] arr, function(Type) returns (Type1) func)
Applies a function to each member of an array and returns an array of the results.
Parameters
- arr Type[]
-
the array
-
func
function(Type) returns (Type1) -
a function to apply to each member
-
Return Type
(Type1[]) new array containing result of applying
functo each member ofarrin order
pop
(Type[] arr)
returns TypeRemoves and returns the last member of an array. The array must not be empty.
Parameters
- arr Type[]
-
the array
-
Return Type
(Type) removed member
push
(Type[] arr, Type... vals)
Adds values to the end of an array.
Parameters
- arr Type[]
-
the array
- vals Type...
-
values to add to the end of the array
reduce
(Type[] arr, function(Type1, Type) returns (Type1) func, Type1 initial)
Combines the members of an array using a combining function. The combining function takes the combined value so far and a member of the array, and returns a new combined value.
Parameters
- arr Type[]
-
the array
-
func
function(Type1, Type) returns (Type1) -
combining function
- initial Type1
-
initial value for the first argument of combining parameter
func
-
Return Type
(Type1) result of combining the members of
arrusingfuncFor example
reduce([1, 2, 3], function (int total, int n) returns int { return total + n; }, 0)is the same as
sum(1, 2, 3).
remove
(Type[] arr, int index)
returns TypeRemoves a member of an array.
Parameters
- arr Type[]
-
the array
- index int
-
index of member to be removed from
arr
-
Return Type
(Type) the member of
arrthat was atindexThis removes the member ofarrwith indexindexand returns it. It panics if there is no such member.
removeAll
(any | error[] arr)
Removes all members of an array.
Parameters
- arr any | error[]
-
the array Panics if any member cannot be removed.
reverse
(Type[] arr)
returns Type[]Reverses the order of the members of an array.
Parameters
- arr Type[]
-
the array to be reversed
-
Return Type
(Type[]) arrwith its members in reverse order
setLength
(any | error[] arr, int length)
Changes the length of an array.
Parameters
- arr any | error[]
-
the array of which to change the length
- length int
-
new length
setLength(arr, 0)is equivalent toremoveAll(arr).
shift
(Type[] arr)
returns TypeRemoves and returns first member of an array. The array must not be empty.
Parameters
- arr Type[]
-
the array
-
Return Type
(Type) the value that was the first member of the array
slice
(Type[] arr, int startIndex, int endIndex)
returns Type[]Returns a subarray starting from startIndex (inclusive) to endIndex (exclusive).
Parameters
- arr Type[]
-
the array
- startIndex int
-
index of first member to include in the slice
- endIndex int (default arr.length(arr))
-
index of first member not to include in the slice
-
Return Type
(Type[]) array slice within specified range
sort
(Type[] arr, function(Type, Type) returns (int) func)
Sorts an array using a comparator function. The comparator function must return a value less than, equal to or greater than zero according as its first argument is to be ordered before, equal to or after its second argument.
Parameters
- arr Type[]
-
the array to be sorted
-
func
function(Type, Type) returns (int) -
comparator function
-
Return Type
(Type[]) arrwith its members sorted
toBase16
(byte[] arr)
returns stringReturns the string that is the Base16 representation of an array of bytes.
The representation is the same as used by a Ballerina Base16Literal.
The result will contain only characters 0..9, a..f.
There will be no whitespace in the returned string.
Parameters
- arr byte[]
-
the array
-
Return Type
(string) Base16 string representation
toBase64
(byte[] arr)
returns stringReturns the string that is the Base64 representation of an array of bytes.
The representation is the same as used by a Ballerina Base64Literal.
The result will contain only characters A..Z, a..z, 0..9, +, / and =.
There will be no whitespace in the returned string.
Parameters
- arr byte[]
-
the array
-
Return Type
(string) Base64 string representation
toStream
(Type[] arr)
returns stream<Type>Returns a stream from the given array.
Parameters
- arr Type[]
-
The array from which the stream is created
-
Return Type
(stream<Type>) The stream representation of the array
arr
unshift
(Type[] arr, Type... vals)
Adds values to the start of an array.
The values newly added to the array will be in the same order
as they are in vals.
Parameters
- arr Type[]
-
the array
- vals Type...
-
values to add to the start of the array