Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
How to resize an array in Java?
An array cannot be resized dynamically in Java.
- One approach is to use java.util.ArrayList(or java.util.Vector) instead of a native array.
- Another approach is to re-allocate an array with a different size and copy the contents of the old array to the new array.
Example:
class ResizableArray {
public static void main (String[] args) {
int[] a = {1, 2, 3};
a = (int[])resizeArray(a, 5);
a[3] = 4;
a[4] = 5;
for (int i=0; i<a.length; i++)
System.out.println(a[i]);
}
private static Object resizeArray (Object oldArray, int newSize) {
int oldSize = java.lang.reflect.Array.getLength(oldArray);
Class elementType = oldArray.getClass().getComponentType();
Object newArray = java.lang.reflect.Array.newInstance(elementType, newSize);
int preserveLength = Math.min(oldSize, newSize);
if (preserveLength > 0)
System.arraycopy(oldArray, 0, newArray, 0, preserveLength);
return newArray;
}
}
Output:
1 2 3 4 5
Updated on: 30-Jul-2019
4K+ Views
Advertisements