Why Does Member Initialization Order in C Constructors Differ from the Initializer List Order?

Member Initializer List Evaluation Order

When working with constructors that initialize class members, it's crucial to understand the order in which these initializations occur. Let's explore a scenario where the expected initialization order was not followed, leading to unexpected behavior.

In the provided code, a class A is defined with member variables a_ and b_. The constructor takes arguments to initialize both members. The programmer assumed that the members would be initialized in the listed order: first a_ and then b_. However, in a specific instance, it was observed that b_ was initialized before a_, causing an abort when a_ was referenced before its initialization.

To ensure the correct order of initialization, it's essential to know that the order is determined by the data member declarations in the class definition. In the example above, a_ is declared first in the class, followed by b_. Therefore, a_ will always be initialized before b_, regardless of the order in the member initializer list, resolving the issue encountered by the programmer.

The above is the detailed content of Why Does Member Initialization Order in C Constructors Differ from the Initializer List Order?. For more information, please follow other related articles on the PHP Chinese website!