Example explained. Line 1: #include is a header file library that lets us work with input and output objects, such as cout (used in line 5). Header files add functionality to C programs. Line 2: using namespace std means that we can use names for objects and variables from the standard library. C cout The cout object in C is an object of class ostream. It is used to display the output to the standard output device i.e. It is associated with the standard C output stream stdout.
C/C++ support for Visual Studio Code is provided by a Microsoft C/C++ extension to enable cross-platform C and C++ development on Windows, Linux, and macOS.
Getting started
C/C++ compiler and debugger
The C/C++ extension does not include a C++ compiler or debugger. You will need to install these tools or use those already installed on your computer.
Popular C++ compilers are:
- GCC on Linux
- GCC via Mingw-w64 on Windows
- Microsoft C++ compiler on Windows
- Clang for XCode on macOS
Make sure your compiler executable is in your platform path so the extension can find it. You can check availability of your C++ tools by opening the Integrated Terminal (⌃` (Windows, Linux Ctrl+`)) in VS Code and try running the executable (for example
g++ --help
).Install the Microsoft C/C++ extension
- Open VS Code.
- Click the Extensions view icon on the Sidebar (⇧⌘X (Windows, Linux Ctrl+Shift+X)).
- Search for
c++
. - Click Install.
Hello World tutorials
Get started with C++ and VS Code with Hello World tutorials for your environment:
Documentation
You can find more documentation on using the Microsoft C/C++ extension under the C++ section, where you'll find topics on:
Remote Development
VS Code and the C++ extension support Remote Development allowing you to work over SSH on a remote machine or VM, inside a Docker container, or in the Windows Subsystem for Linux (WSL).
To install support for Remote Development:
- Install the VS Code Remote Development Extension Pack.
- If the remote source files are hosted in WSL, use the Remote - WSL extension.
- If you are connecting to a remote machine with SSH, use the Remote - SSH extension.
- If the remote source files are hosted in a container (for example, Docker), use the Remote - Containers extension.
Feedback
If you run into any issues or have suggestions for the Microsoft C/C++ extension, please file issues and suggestions on GitHub. If you haven't already provided feedback, please take this quick survey to help shape this extension for your needs.
Formatting output in C++, is important in the development of the output screen, which can be easily read and understood. C++ offers the programmer several input/output manipulators. Two of these (widely used) I/O manipulators are:
- setw()
- setprecision()
In order to use these manipulators, you must include the header file named iomanip.h. Here is an example, showing how to include this header file in your C++ program.
The setw() Manipulator
In C++, the setw() manipulators sets the width of the field assigned for the output. It takes the size of the field (in number of characters) as parameter. Here is an example, this code fragment:
generates the following output on the screen (each underscore represents a blank space).
The setw() manipulator does not stick from one cout statement to the next. For example, if you want to right-justify three numbers within an 8-space field, you will need to repeat setw() for each value, as it shown below:
The output will be (each underscore represents a blank space):
C++ Formatting Output Example
Here are some example program demonstrating, how to format the output screen in C++
Here is the sample run of the above C++ program:
Here another type of C++ program, also demonstrating, output formatting in C++
Here is the sample run of this C++ program:
The setprecision() manipulator
In C++, the setprecision() manipulator sets the total number of digits to be displayed when floating-point numbers are printed. Here is an example, this code fragment:
will print the following output to the screen (notice the rounding) :
The setprecision() manipulator can also be used to set the number of decimal places to be displayed. In order for setprecision() to accomplish this task, you will have to set an ios flag. The flag is set with the following statement :
Dev C++ Cout
Once the flag has been set, the number you pass to setprecision() is the number of decimal places you want displayed. The following code:
generates the following output on the screen (notice no rounding):
Additional IOS flags
In the statement:
'fixed' i.e., ios::fixed is referred to as a format option. Other possible format options can be one of the following :
Format Value | Meaning |
---|---|
left | left-justify the output |
right | right-justify the output |
showpoint | displays decimal point and trailing zeros for all floating point numbers, even if the decimal places are not needed |
uppercase | display the 'e' in E-notation as 'E' rather than 'e' |
showpos | display a leading plus sign before positive values |
scientific | display floating point numbers in scientific ('E') notation |
fixed | display floating point numbers in normal notation - no trailing zeroes and no scientific notation |
You can remove these options by replacing setf(used with cout, recall cout.setf) with unsetf. For example, to get 5.8 to display as 5.80, the following lines of code are needed :
C++ Cout Include
Please note that all the subsequent couts retain the precision set with the last setprecision(). That means setprecision() is 'sticky'. Whatever precision you set, sticks with the cout device until such time as you change it with an additional setprecision() later in the program.