One of the main data types of programming is the string. Strings are important in every step of programming. They should be used carefully so they are displayed and function correctly which is especially important if you are developing global applications that use different languages. Using a professional C++ Dev Tool will help you with things like automatic syntax highlighting to help you quickly scan your code for mistakes and manage string literals for things like translation into other human languages.
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Why is it important to declare and use string literals properly in Modern C++?
Using string types incorrectly can impact our app’s performance. We may have problems in some languages that may cause our data loss, and our app may get frozen in some cases when it processes a string type incorrectly. For example, if you have heavy amounts of string outputs from a game in every frame this will slow down the FPS of your game’s performance. If you try to print out strings in multi-task operations this may cause errors and even more crashes in your applications. If you read and convert ‘multibyte’ or Unicode strings in the wrong way you may have a loss of characters, because of Unicode string-to-string or wstring to string operations.
During the development of modern applications, we need to know the String Literals that we use to define the type of a string. A string literal is used to define the representation of strings value within the source code of a computer program. Now let’s see how we can use string literals in C++.
Why do we need string literals in Modern C++?
In the C/C++ programming language, ASCII codes are used as char arrays to store texts in ASCII mode. In early C and C++ versions, we were using char arrays as a string only. More global applications require more global compatibilities as character supports, locale supports, support for emojis, etc. And 8 bits of ASCII forms were not enough to hold these, there were 16 bits of character forms for the strings and 32 bits or more. As a result, we have different string types. This started with string, then wstring, u16string, u32string, UnicodeString, etc. Unicode strings are the most broadly compatible strings that we can use in C++.
Those different character bits require a new way to define, use, and display them.
We can use char arrays in both C and C++, they are faster in operations and have less memory usage. In a modern way, strings are useful for storing texts and they are defined in the string library. A string class contains a collection of characters surrounded by double quotes as we used in char arrays.
When we want to set a string data, they are filled with chars that are between ” and “. This string data can be in different character types.
What are string literals in Modern C++?
A string literal is a letter that represents types of a sequence of characters or escape sequences enclosed in double quotation mark symbols, i.e. “Hello”. A string literal may be prefixed with a string literal letter u, for example u"Hello". Here, u is a string literal for the “Hello” string value.
String literals are used to define character format of a strings. A string literal is used to define the representation of a string value within the source code of a computer program.
How do I define string literals in Modern C++?
Basically, there are 6 string literals, in the first one we use nothing, others are u8, u, U, L, R. Here is a table that we prepared for you that shows all string literals.
| String Literal | Syntax | Char Types | Standard | Example | C++ Examples |
| “string” | char | “Hello” | char *s = “Hello”; String s = “Hello”; | ||
| u8 | char8_t | since C++20 | u8″Hello” | char8_t *s = u8″Hello”; | |
| u | u”string” | char16_t | since C++11 | u”Hello” | char16_t *s = u”Hello”; String s = u”Hello”; UnicodeString s = u”Hello”; |
| U | U”string” | char32_t | since C++11 | U”Hello” | char32_t *s = U”Hello”; String s = U”Hello”; UnicodeString s = U”Hello”; |
| L | L”string” | wchar_t | L”Hello” | wchar_t *s = L”Hello”; | |
| R | R”(rawstring)” | char, char16_t, char32_t, wchar_t | since C++11 | R”Hello” | wchar_t *s = R”(Hello)”; |
Note that, here char8_t is a new type in C++20 and requires the /std:c++20 or /std:c++latest compiler option.
is there an example of using string literals in Modern C++?
If you want to see an example that shows all string literals in usage, here it is,
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#include <iostream> #include <tchar.h> int _tmain(int argc, _TCHAR* argv[]) { char s1[] ="Hello"; // char8_t s2[] = u8"Hello"; // (C++20) char16_t s3[] = u"Hello"; char32_t s4[] = U"Hello"; wchar_t s5[] = L"Hello"; const wchar_t s6[] = LR"(Hello)"; return 0; } |
Where can I find more examples of Unicode string literals in Modern C++?
Here are some more examples of defining and using Unicode string literals in C++.
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