Array
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AI-generated Key Takeaways
The Java Array class provides static methods for dynamic array creation and manipulation, including methods for creating, accessing, and modifying arrays.
It supports widening conversions during get/set operations but throws an IllegalArgumentException for narrowing conversions.
The Array class is primarily used for reflection, operating on Object instances representing arrays, and is less common for standard array operations.
Exceptions like NullPointerException, IllegalArgumentException, and ArrayIndexOutOfBoundsException are thrown for invalid arguments or array access issues.
Direct array creation (e.g., int[] myArray = new int[5]) is generally preferred for non-reflective scenarios, while Array class methods are useful for reflection-based tasks.
The Array class provides static methods to dynamically create and
access Java arrays.
Array permits widening conversions to occur during a get or set
operation, but throws an IllegalArgumentException if a narrowing
conversion would occur.
public
static
ObjectnewInstance(Class<?> componentType, int... dimensions)
Creates a new array
with the specified component type and dimensions.
If componentType
represents a non-array class or interface, the new array
has dimensions.length dimensions and
componentType as its component type. If
componentType represents an array class, the
number of dimensions of the new array is equal to the sum
of dimensions.length and the number of
dimensions of componentType. In this case, the
component type of the new array is the component type of
componentType.
The number of dimensions of the new array must not
exceed 255.
Parameters
componentType
the Class object representing the component
type of the new array
dimensions
an array of int representing the dimensions of
the new array
if the specified dimensions
argument is a zero-dimensional array, if componentType is Void.TYPE, or if the number of dimensions of the requested array
instance exceed 255.
if any of the components in
the specified dimensions argument is negative.
public
static
void
set(Object array, int index, Object value)
Sets the value of the indexed component of the specified array
object to the specified new value. The new value is first
automatically unwrapped if the array has a primitive component
type.
If the specified object argument
is not an array, or if the specified value cannot be converted
to the underlying array's component type by an identity or a
primitive widening conversion
If the specified object argument
is not an array, or if the specified value cannot be converted
to the underlying array's component type by an identity or a
primitive widening conversion
If the specified object argument
is not an array, or if the specified value cannot be converted
to the underlying array's component type by an identity or a
primitive widening conversion
If the specified object argument
is not an array, or if the specified value cannot be converted
to the underlying array's component type by an identity or a
primitive widening conversion
If the specified object argument
is not an array, or if the specified value cannot be converted
to the underlying array's component type by an identity or a
primitive widening conversion
If the specified object argument
is not an array, or if the specified value cannot be converted
to the underlying array's component type by an identity or a
primitive widening conversion
If the specified object argument
is not an array, or if the specified value cannot be converted
to the underlying array's component type by an identity or a
primitive widening conversion
If the specified object argument
is not an array, or if the specified value cannot be converted
to the underlying array's component type by an identity or a
primitive widening conversion
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2024-07-10 UTC."],[],["The `Array` class in Java enables dynamic array handling, supporting runtime creation and manipulation. It allows retrieving and setting array element values with methods like `get`, `getBoolean`, `set`, and `setBoolean`, providing type-specific versions for primitives. The class also supports array creation using `newInstance`, determining array length with `getLength`, implicit type widening, and error handling by throwing exceptions such as `NullPointerException`, `IllegalArgumentException`, and `ArrayIndexOutOfBoundsException` for invalid array access.\n"]]
