Understanding Member Initialization in Classes
In C , when creating classes, members can be initialized explicitly or implicitly. If not explicitly initialized, the behavior depends on the type of member.
Initialization of Member Variables
-
Primitive Types: Primitive types (e.g., int, pointers) are not initialized by default. They contain arbitrary values present in memory when declared.
-
Objects: Objects of classes are initialized by calling their default constructor. If there's no default constructor defined, you must explicitly initialize them.
-
References: References must be always initialized to an existing reference; otherwise, the compiler will throw an error.
Member Initialization in Example
Consider the following class:
class Example {
private:
int *ptr;
string name;
string *pname;
string &rname;
const string &crname;
int age;
public:
Example() {}
};
If an instance of this class (Example ex) is created without explicit initialization, the members are initialized as follows:
-
ptr: Contains junk
-
name: Empty string
-
pname: Contains junk
-
rname: Compile error (reference must be initialized)
-
crname: Compile error (const reference must be initialized)
-
age: Contains junk
Implications for Best Practices
Understanding member initialization is crucial for writing error-free programs. To ensure proper behavior:
- Explicitly initialize primitive types and pointers to prevent unexpected values.
- Ensure that references are initialized to valid references or thrown an error.
- Define default constructors or explicitly initialize objects to avoid undefined behavior.
The above is the detailed content of How are Class Members Initialized in C , and What are the Best Practices?. For more information, please follow other related articles on the PHP Chinese website!
Statement:The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn