More Effective C ++ Reading Notes 1.

Item 1: difference between pointer and reference

1. the pointer can be null, and the reference cannot be referenced. The advantage of null is that the judgment can be omitted to improve the code efficiency.

[Cpp]
01. void Test (const int & count)
02 .{
03. cout <count <endl;
04 .}
05.
06. void Test (const int * count)
07 .{
08. if (NULL! = Count)
09 .{
10. cout <count <endl;
11 .}
12 .}
Void Test (const int & count)
{
Cout <count <endl;
}

Void Test (const int * count)
{
If (NULL! = Count)
{
Cout <count <endl;
}
} 2 the pointer can be changed and cannot be changed after the reference is initialized.
3. Some operators may need to return references when being overloaded.

That is to say, when a null value is possible, the pointer should be used, and when a variable may change, the pointer should be used.