The table summarizes the array functions available in APL.

FunctionDescription
array_concatConcatenates a number of dynamic arrays to a single array.
array_iffReturns a new array containing elements from the input array that satisfy the condition.
array_index_ofSearches the array for the specified item, and returns its position.
array_lengthCalculates the number of elements in a dynamic array.
array_reverseReverses the order of the elements in a dynamic array.
array_rotate_leftRotates values inside a dynamic array to the left.
array_rotate_rightRotates values inside a dynamic array to the right.
array_select_dictSelects a dictionary from an array of dictionaries.
array_shift_leftShifts the values inside a dynamic array to the left.
array_shift_rightShifts values inside an array to the right.
array_sliceExtracts a slice of a dynamic array.
array_splitSplits an array to multiple arrays according to the split indices and packs the generated array in a dynamic array.
array_sumCalculates the sum of elements in a dynamic array.
isarrayChecks whether a value is an array.
pack_arrayPacks all input values into a dynamic array.
strcat_arrayTakes an array and returns a single concatenated string with the array’s elements separated by the specified delimiter.

Dynamic arrays

Most array functions accept a dynamic array as their parameter. Dynamic arrays allow you to add or remove elements. You can change a dynamic array with an array function.

A dynamic array expands as you add more elements. This means that you don’t need to determine the size in advance.