Menu
×
   ❮     
HTML CSS JAVASCRIPT SQL PYTHON JAVA PHP HOW TO W3.CSS C C++ C# BOOTSTRAP REACT MYSQL JQUERY EXCEL XML DJANGO NUMPY PANDAS NODEJS R TYPESCRIPT ANGULAR GIT POSTGRESQL MONGODB ASP AI GO KOTLIN SASS VUE DSA GEN AI SCIPY CYBERSECURITY DATA SCIENCE
     ❯   

C++ Tutorial

C++ HOME C++ Intro C++ Get Started C++ Syntax C++ Output C++ Comments C++ Variables C++ User Input C++ Data Types C++ Operators C++ Strings C++ Math C++ Booleans C++ If...Else C++ Switch C++ While Loop C++ For Loop C++ Break/Continue C++ Arrays C++ Structures C++ Enums C++ References C++ Pointers

C++ Functions

C++ Functions C++ Function Parameters C++ Function Overloading C++ Scope C++ Recursion

C++ Classes

C++ OOP C++ Classes/Objects C++ Class Methods C++ Constructors C++ Access Specifiers C++ Encapsulation C++ Inheritance C++ Polymorphism C++ Files C++ Exceptions C++ Date

C++ Data Structures

C++ Data Structures & STL C++ Vectors C++ List C++ Stacks C++ Queues C++ Deque C++ Sets C++ Maps C++ Iterators C++ Algorithms

C++ How To

C++ Add Two Numbers C++ Random Numbers

C++ Reference

C++ Reference C++ Keywords C++ <iostream> C++ <fstream> C++ <cmath> C++ <string> C++ <cstring> C++ <ctime> C++ <vector> C++ <algorithm>

C++ Examples

C++ Examples C++ Real-Life Examples C++ Compiler C++ Exercises C++ Quiz C++ Syllabus C++ Study Plan C++ Certificate


C++ clog object

❮ iostream objects


Example

Use the clog object to output log messages:

int myNum = 12;

clog << "The number " << myNum << " was given\n";

Try it Yourself »


Definition and Usage

The clog object is used to log messages about the state of the program. It behaves identically to cout but it can be directed to a different destination such as a log file. clog and cerr always write to the same destination.

For more detailed usage, see the <iostream> cout object.

While clog and cerr write to the same destination, clog is buffered and cerr is not. A buffered output stores the output temporarily in a variable and does not write to the destination until certain conditions are met. Buffered outputs are more efficient because they do fewer write operations on files. If the messages are important, use cerr instead because otherwise they may be lost if the program crashes.

Note: The clog object is defined in the <iostream> header file.


More Examples

Example

Direct clog to write to a file instead of to the console:

#include <iostream>
#include <fstream>
using namespace std;

int main() {
  int myNum = 12;

  // Set "info.log" as the output file for the log messages
  ofstream log("info.log");
  clog.rdbuf(log.rdbuf());
  
  // Write to the log file
  clog << "The number " << myNum << " was given\n";

  // Close the file
  log.close();
  
  return 0;
}

❮ iostream objects