linux c 字符串常量定义的几种方式
英文版
Title: Several Methods of Defining String Constants in Linux C
In the Linux C programming environment, defining string constants is a fundamental task that often arises. Here are several common methods to accomplish this:
Direct Assignment:
The simplest way to define a string constant is by directly assigning it to a character array. For example:
    cCopy char str[] = "Hello, World!";
          char str[] = "Hello, World!";
In this case, the compiler automatically allocates memory for the array, including the null terminator.
2. Using String Literals:
String literals are constant character arrays that can be assigned to pointer variables. However, modifying a string literal is undefined behavior. For instance:
    cCopy char *ptr = "Hello, World!";
          char *ptr = "Hello, World!";
linux字符串转数组
Here, ptr points to a read-only memory location where the string literal is stored.
3. Using the const Keyword:
When you want to ensure that a string won't be modified, you can use the const keyword. This is especially useful when passing strings to functions that shouldn't modify them:
    cCopy const char *constStr = "Immutable String";
          const char *constStr = "Immutable String";
Initializing with String Literals and Modifying Copies:
If you want to modify a string while still using a string literal as a starting point, you can create a copy of the string literal and then modify that copy:
    cCopy char modifiableStr[] = "Original String";
modifiableStr[0] = 'M';  // Now modifiableStr is "Modified String"
          char modifiableStr[] = "Original String";
modifiableStr[0] = 'M';  // Now modifiableStr is "Modified String"
Using the Preprocessor:
The C preprocessor, #define, can also be used to define string constants. This is useful for constants that need to be referenced multiple times throughout the code:
    cCopy #define GREETING "Hello, User!"
/
/ ...
printf("%s\n", GREETING);
          #define GREETING "Hello, User!"
// ...
printf("%s\n", GREETING);
Remember, when dealing with strings in C, it's crucial to understand the difference between string literals (which are constant and reside in read-only memory) and character arrays (which can be modified). Understanding these differences will help avoid common pitfalls and ensure the stability of your program.
中文版
标题：Linux C中定义字符串常量的几种方法
在Linux C编程环境中，定义字符串常量是一项基本任务。以下是几种实现此目标的常见方法：
直接赋值：
定义字符串常量最简单的方法是通过直接将其赋值给字符数组。例如：
    cCopy char str[] = "Hello, World!";
          char str[] = "Hello, World!";

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