Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
A Puzzle on C/C++ R-Value Expressions?
Here we will see one puzzle. Suppose there is a program which is given as below, we have to tell what will be the output and why?
Example
#include<iostream>
using namespace std;
int main() {
int x = 0xab;
~x;
cout << hex << x;
}So what will be the output? The ~x is doing the complement operation. So is it show the complemented result in hex form?
Well the output is like the following
Output
ab
So, there is no change. But why? The reason is ~x is converting x into its complemented form, but that value is not assigned to any variable. The expression is R-value expression. Until the Lvalue is used it will not be stored into some variables. If we put L-value it will be look like this −
Example
#include<iostream>
using namespace std;
int main() {
int x = 0xab;
x = ~x;
cout << hex << x;
}Output
ffffff54
Updated on: 31-Jul-2019
79 Views
Advertisements