• 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
  • Liutauras Vilda
  • Tim Cooke
  • Jeanne Boyarsky
  • Paul Clapham
Sheriffs:
  • Devaka Cooray
  • Ron McLeod
  • paul wheaton
Saloon Keepers:
  • Tim Moores
  • Piet Souris
  • Tim Holloway
  • Stephan van Hulst
  • Carey Brown
Bartenders:
  • Al Hobbs
  • Frits Walraven
  • Scott Selikoff

short circuit operators

 
Ranch Hand
Posts: 36
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
1.public static ShortCkt {
public static void main(String args[]) {
int i = 0;
boolean t = true;
boolean f = false, b;
b = (t && ((i++) == 0));
b = (f && ((i+=2) > 0));
System.out.println(i);
}
}
answer is 1.

2.public static ShortCkt {
public static void main(String args[]) {
int i = 0;
boolean t = true;
boolean f = false, b;
b = (t & ((i++) == 0));
b = (f & ((i+=2) > 0));
System.out.println(i);
}
}


0
1
2
3
answer is 3.
Please explain?




0
1
2
3
 
Ranch Hand
Posts: 30
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
first answer

initially i=0;
in the sixth line it is incremented

so the final answer is 1....

second answer

same logic
i=0
6th line it is incremented by 1...so i=1
in the next line it is incremented by 2...so i=i+2>>>i=1+2

answer is 3
 
Greenhorn
Posts: 28
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
1.1.public static ShortCkt {
2.public static void main(String args[]) {
3.int i = 0;
4.boolean t = true;
5.boolean f = false, b;
6.b = (t && ((i++) == 0));
7.b = (f && ((i+=2) > 0));
8.System.out.println(i);
}
}
answer is 1.

2.1.public static ShortCkt {
2.public static void main(String args[]) {
3.int i = 0;
4.boolean t = true;
5.boolean f = false, b;
6.b = (t & ((i++) == 0));
7.b = (f & ((i+=2) > 0));
8.System.out.println(i);
}
}

Code 1 uses short circuit operator "&&". This evaluates the second part of the expression only if the first part is true. If the first part is false, the second part of the expression is ignored.
In line 6, in the first part, t is true. Hence, the second part is evaluated and i is incremented to 1.In line 7, first part, f is false so, the second half of the expression is ignored. Hence, i = 1.

Code 2 uses logical "&" operator. Hence both expressions are evaluated and i = 3.

Hope you are clear with the answer.
 
suresh koutam
Ranch Hand
Posts: 30
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Ram...

this code has nothing to do with the short Circuit operators...they are asking the value of i....which you can evaluate just looking at the increment operators....its another way of confusing scjp aspirants....
 
Ranch Hand
Posts: 377
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

Originally posted by suresh koutam:
this code has nothing to do with the short Circuit operators...they are asking the value of i....which you can evaluate just looking at the increment operators....its another way of confusing scjp aspirants....



If this code has nothing to do with the short circuit operators, then I ask you for the detailed explanation why the outputs are different.
 
Ranch Hand
Posts: 148
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Suresh,

The output of the first example does depend on the short circuit operation.

This line of code


does not change the value of i due to the += operator being on the right-hand side of the short circuit && operator when the left-hand side is false.
 
suresh koutam
Ranch Hand
Posts: 30
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
sorry guys..i was little excited seeing the answers...i agree with you guys..
thanks for correcting...


Suresh Koutam
 
Right! We're on it! Let's get to work tiny ad!
the value of filler advertising in 2021
https://coderanch.com/t/730886/filler-advertising
reply
    Bookmark Topic Watch Topic
  • New Topic