Can the size of dynamic array be changed?

0 votes
Jun 12, 2018 in Java by scarlett
• 1,280 points
45 views

2 answers to this question.

0 votes

No, you can't change the size of an array once created. You either have to allocate it bigger than you think you'll need or accept the overhead of having to reallocate it needs to grow in size. When it does you'll have to allocate a new one and copy the data from the old to the new:

int oldItems[] = new int[10];
for (int i=0; i<10; i++) {
  oldItems[i] = i+10;
}
int newItems[] = new int[20];
System.arraycopy(oldItems, 0, newItems, 0, 10);
oldItems = newItems;
answered Jun 12, 2018 by Akrati
• 960 points
0 votes
import java.util.List;
import java.util.ArrayList;
import java.util.Random;

public class A  {

    public static void main( String [] args ) {
        // dynamically hold the instances
        List<xClass> list = new ArrayList<xClass>();

        // fill it with a random number between 0 and 100
        int elements = new Random().nextInt(100);  
        for( int i = 0 ; i < elements ; i++ ) {
            list.add( new xClass() );
        }

        // convert it to array
        xClass [] array = list.toArray( new xClass[ list.size() ] );


        System.out.println( "size of array = " + array.length );
    }
}
class xClass {}
answered Aug 31, 2018 by Sushmita
• 6,880 points

Related Questions In Java

0 votes
1 answer

what are the ways in which a list can be iterated

  There are 5 ways to iterate over ...READ MORE

answered Apr 23, 2018 in Java by sharth
• 3,350 points
61 views
0 votes
2 answers

What is the use of toString method in Java and how can I use it ?

Whenever you require to explore the constructor ...READ MORE

answered Aug 23, 2018 in Java by Daisy
• 8,050 points
806 views
0 votes
2 answers

How can I invoke a method when the method name is in the form of a given string?

You could probably use method invocation from reflection: Class<?> ...READ MORE

answered Aug 19 in Java by Sirajul
• 37,080 points
71 views
0 votes
2 answers

How can I get the filenames of all files in a folder which may or may not contain duplicates

List<String> results = new ArrayList<String>(); File[] files = ...READ MORE

answered Sep 12, 2018 in Java by Sushmita
• 6,880 points
621 views
+5 votes
3 answers

How to execute a python file with few arguments in java?

You can use Java Runtime.exec() to run python script, ...READ MORE

answered Mar 27, 2018 in Java by DragonLord999
• 8,380 points

edited Nov 6, 2018 by Omkar 10,176 views
0 votes
1 answer

How to handle drop downs using Selenium WebDriver in Java

First, find an XPath which will return ...READ MORE

answered Mar 27, 2018 in Selenium by nsv999
• 5,110 points
2,280 views
0 votes
1 answer

What are the differences between getText() and getAttribute() functions in Selenium WebDriver?

See, both are used to retrieve something ...READ MORE

answered Apr 5, 2018 in Selenium by nsv999
• 5,110 points
5,924 views
0 votes
1 answer

Selenium JARS(Java) missing from downloadable link

Nothing to worry about here. In the ...READ MORE

answered Apr 5, 2018 in Selenium by nsv999
• 5,110 points
691 views
0 votes
1 answer

Can quotes be added in a java string.how?

In Java, you can escape quotes with \: String ...READ MORE

answered Jun 14, 2018 in Java by Akrati
• 960 points
29 views
0 votes
1 answer

What is the use of StringBuilder in java?

If you use String concatenation in a ...READ MORE

answered Jun 19, 2018 in Java by Akrati
• 960 points
79 views