What is ArrayUtils.getLength in Java?
getLength is a static method of the ArrayUtils class that returns the number of elements in the given array (i.e., the length of the given array).
This method can deal with both object type arrays as well as primitive type arrays.
Example 1
- array =
[1,2,3,4,5]
Applying the getLength function will result in 5 as the array’s length is 5.
Example 2
- array =
null
Applying the getLength function will result in 0 as the array passed is null.
ArrayUtils is defined in the Apache Commons Lang package. Apache Commons Lang can be added to the Maven project by adding the following dependency to the pom.xml file.
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.12.0</version>
</dependency>
For other versions of the commons-lang package, refer to the Maven Repository.
You can import the ArrayUtils class as follows:
import org.apache.commons.lang3.ArrayUtils;
Syntax
public static int getLength(Object array)
Parameters
Object array- the array to find the length of.
Return value
The function returns the length of the array.
0is returned if the array points tonull.
IllegalArgumentExceptionis returned if the passed argument is not an array.
Code
import org.apache.commons.lang3.ArrayUtils;public class Main {public static void main(String[] args) {int[] array = {1,2,3,4,5};System.out.println(ArrayUtils.getLength(array));System.out.println(ArrayUtils.getLength(null));System.out.println(ArrayUtils.getLength("hello"));}}
Expected output
5
0
Exception in thread "main" java.lang.IllegalArgumentException: Argument is not an array
at java.base/java.lang.reflect.Array.getLength(Native Method)
at org.apache.commons.lang3.ArrayUtils.getLength(ArrayUtils.java:1710)
at Main.main(Main.java:9)
The code above throws an exception in the last statement of the main method, as the passed argument to the getLength method is not an array.