Javatpoint Logo
Javatpoint Logo

iswgraph() in C/C++


Character handling is a fundamental C and C++ programming aspect that requires careful consideration. Iswgraph() is an exciting function that helps developers manage wide characters. This function, which is located in the wctype.h header file is a valuable tool for character classification. In this article, we'll look into the complexities of iswgraph(), learning its purpose, usage, and importance in the world of wide characters.

Understanding iswgraph():

At its core, iswgraph() is a wide character classification function designed to determine whether a given wide character is a graphical character. In simpler terms, it helps programmers identify characters with a visual representation when printed or displayed. It includes characters like letters, digits, and punctuation marks.

1. Prototype and Syntax:

The prototype of iswgraph() is as follows:

Here, 'wint_t' is a broad integer type representing any wide character, and 'wc' is the wide character in question. The function returns a non-zero value if the character is graphical and zero otherwise.

2. Parameters

wc - It is a wide character that needs to be tested. It is passed as a variable of the wint_t data type defined in wchar.h header file.

wint_t is an integer type that can store any valid comprehensive character code. It is an unsigned integer type and is usually 32-bit wide.

The wc parameter will contain the numeric code for the wide-character based on the encoding scheme (typically UTF-32 or UTF-16).

For example, if you want to test whether the wide character 'A' is printable, you will pass the numeric code value of 'A' (65 in ASCII encoding) cast to a wint_t type variable.

So, wc essentially contains the encoded integer value representing the Unicode code point for the wide character that needs to be tested by the iswgraph() function. After that, the function checks if this character has a graphical glyph representation in the current locale.

3. Return Value

The iswgraph() function returns an integer value indicating whether or not the wide character wc is a printable graphical character.

The return type is 'int'. The possible return values are:

Non-zero value - The wide-character represented by wc is a printable graphical character in the current locale. It could be any positive integer value, typically 1.

The wide-character represented by wc is NOT a printable graphical wide character. It could be a control code, whitespace, null terminator, etc., not occupying a printing position on the screen.

It makes it easy to check in code. Test if the return value is > 0 to see if the wc is a printable graphical character.

Usage Examples:

Let us dive into some practical examples to illustrate the application of iswgraph():

Example 1:


The character is a graphical character.


In this example, the program checks whether the wide character 'A' is a graphical character using iswgraph(). If it is, a corresponding message is printed to the console.

Example 2:

Let us take an example to Iterating Through a Wide String in C:


H is a graphical character.
e is a graphical character.
l is a graphical character.
l is a graphical character.
o is a graphical character.
1 is a graphical character.
2 is a graphical character.
3 is a graphical character.
! is a graphical character.


In this example, the program iterates through a wide string, identifies, and prints all graphical characters. Showcases the practical utility of iswgraph() in processing wide strings.

Example 3:


Character 'A' is graphical.
Character ' ' is not graphical.
Character '1' is graphical.

Significance in Internationalization:

The iswgraph() function is particularly significant in internationalization, where different languages may use various characters. Since it is designed to handle wide characters, it can be crucial for applications that require support for various languages and character sets.

Consider a scenario where a program needs to process and display text in languages with diverse character sets, such as Chinese or Arabic. Identifying graphical characters becomes essential for ensuring the correct rendering and presentation of the text.

Limitations and Alerts:

While iswgraph() is a powerful tool, it's essential to be aware of its limitations. The function primarily focuses on identifying graphical characters but doesn't provide information about the specific type of graphical character or its formatting.

Additionally, developers should remember that the behavior of iswgraph() depends on the current locale. The function's outcome may vary based on the language and region settings of the system. Therefore, it's crucial to set the appropriate locale using functions like setlocale() if internationalization support is a requirement.

Moreover, iswgraph() becomes increasingly valuable in scenarios where the differentiation between graphical and non-graphical characters is pivotal for program logic. For instance, in text parsing applications, the ability to filter out non-graphical characters efficiently can significantly streamline the processing of textual data.

The versatility of iswgraph() is further underscored by its integration into broader frameworks such as the Standard Template Library (STL) in C++. This inclusion enables developers to leverage the function seamlessly with other language features, fostering a more modular and extensible codebase.

As programming languages evolve to accommodate diverse requirements, iswgraph() remains a steadfast companion for developers navigating the intricate landscape of character handling. Whether in internationalization efforts or everyday text processing tasks, the insights provided by iswgraph() illuminate a path towards more robust, language-aware, and visually appealing software solutions.


In C and C++ programming, iswgraph() is a valuable asset for handling wide characters and facilitating character classification. Its ability to discern graphical characters is particularly beneficial in scenarios involving diverse character sets, making it a valuable tool for internationalization.

Understanding and utilizing the potential of iswgraph() offers new possibilities for developers, allowing them to design robust and language-independent apps. As programming continues to evolve, the importance of functions like iswgraph() in managing wide characters will persist, contributing to developing more versatile and globally accessible software.

Youtube For Videos Join Our Youtube Channel: Join Now


Help Others, Please Share

facebook twitter pinterest

Learn Latest Tutorials


Trending Technologies

B.Tech / MCA