Why is the memory usage ZERO bytes of this program

[Mustafa Garhi]

   
package size.of;

import java.util.ArrayList;
import java.util.List;

class SearchDropDownValues {
	private int id;
	private String fullName;
	
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getFullName() {
		return fullName;
	}
	public void setFullName(String fullName) {
		this.fullName = fullName;
	}
	
	
}

public class MemoryCalculator {
	static List<SearchDropDownValues> list = new ArrayList<SearchDropDownValues>();
	public static void main(String[] args) {
		long totalInitial = Runtime.getRuntime().totalMemory();
		long freeInitial = Runtime.getRuntime().freeMemory();
		final long usedInitial = (totalInitial - freeInitial);
		for(int i = 0; i< 10; i++) {
			SearchDropDownValues downValues = new SearchDropDownValues();
			downValues.setId(i);
			downValues.setFullName("Abcde"+i);
			list.add(downValues);
		}
		long totalFinal = Runtime.getRuntime().totalMemory();
		long freeFinal = Runtime.getRuntime().freeMemory();
		final long usedFinal = (totalFinal - freeFinal);
		System.out.println(usedFinal - usedInitial);
	}
	
}

I always get 0 as the System Print

However if i increase the size of for loop it fetches me some bytes as the output.

Have been scratching my head since quite a time now

Any help would be appreciated.

[David Newton]

Please UseCodeTags when posting code or configuration. Unformatted code and configuration is unnecessarily difficult to read.

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[Mustafa Garhi]

Thanks bro ..

It looks neater now .

[David Newton]

It does :)

The numbers returned by these calls are approximate and don't necessarily reflect exact memory usage statistics (you'd probably need to use the JVM hooks for exact details). Use a higher number and you'll start seeing a difference at some point. *Which* point is likely JVM- and runtime-option dependent. For example, on my Ubuntu machine, I get a non-zero value if I change the count to 235, and that value stays constant again up until 788, at which point it more than doubles.