What does a C++ reference mean?

C++ references are essentially aliases that refer to existing variables or objects, providing a concise and convenient way to manipulate variables while reducing memory consumption and improving program efficiency.

The quoted syntax involves adding an ‘&’ symbol before the variable name, for example:

int a = 5;
int& b = a; // b是a的引用

In the example above, variable b is a reference to variable a, meaning they actually point to the same memory address. Therefore, any modifications made to b directly affect the value of a.

The main features of the citation are as follows:

1. Quotes must be initialized at the time of declaration and the bound object cannot be changed.
2. The relationship between a reference and the original variable is one-to-one; once a reference is established, it cannot be used to reference other variables.
3. Quotes can be used directly like regular variables without the need to access them through the dereference operator (*).

References are also commonly used in passing function parameters, allowing the modification of variables outside the function. This type of reference is known as a function reference parameter.