• Post Reply Bookmark Topic Watch Topic
  • New Topic
programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other Pie Elite all forums
this forum made possible by our volunteer staff, including ...
Marshals:
  • Campbell Ritchie
  • Tim Cooke
  • Devaka Cooray
  • Ron McLeod
  • Jeanne Boyarsky
Sheriffs:
  • Liutauras Vilda
  • paul wheaton
  • Junilu Lacar
Saloon Keepers:
  • Tim Moores
  • Stephan van Hulst
  • Piet Souris
  • Carey Brown
  • Tim Holloway
Bartenders:
  • Martijn Verburg
  • Frits Walraven
  • Himai Minh

"==" Question from Kathy's Book

 
Greenhorn
Posts: 8
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Given the following,
import java.awt.Button;
class CompareReference {
public static void main (String [] args){
float f = 42.0f;
float [] f1 = new float[2];
float [] f2 = new float[2];
float [] f3 = f1;
long x = 42;
f1[0] = 42.0f;
}
}
which three statements are true? (Choose three)
A. f1 == f2
B. f1 == f3
C. f2 == f1[1]
D. x == f1[0]
E. f == f1[0]
The answers are B,D and E.
The question is why D, that is why you are allow to compare a long with a float?
 
Ranch Hand
Posts: 93
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
because of automatic numeric promotion , a long is promoted to a float and the comparison works out to true
 
Ranch Hand
Posts: 3271
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Preeti is right. In this case, we have what is known as binary numeric promotion. You can read all about it in the JLS, sect;5.6.2 Binary Numeric Promotion.
Corey
 
Politics is a circus designed to distract you from what is really going on. So is this tiny ad:
the value of filler advertising in 2021
https://coderanch.com/t/730886/filler-advertising
reply
    Bookmark Topic Watch Topic
  • New Topic