Getting length of a number's bits

Question

  int g = 269;//1_0000_1101
    System.out.println( length(Integer.toBinaryString(g)));

This will print 18(why?), but I want it to print 9. How can I do that?

Answer 1

If you use the Integer object for your whole number, the getObjectSize(Object o) method in the Instrumentation library is your guy: http://docs.oracle.com/javase/7/docs/api/java/lang/instrument/Instrumentation.html

There are a few threads on this.

• Calculate size of Object in Java
• In Java, what is the best way to determine the size of an object?
• http://www.javaworld.com/article/2077496/testing-debugging/java-tip-130--do-you-know-your-data-size-.html

Cheers!

Answer 2

System.out.println(Integer.toBinaryString(g).length());

Would print out the length of the returned String from toBinaryString. You are measuring the length of the statement otherwise.