class SomeClass
{
    private int SomeNumber = 42;
 
    public ReturnValue UseSomeNumber(...)
    {
        int someNumberCopy = this.SomeNumber;
        if (someNumberCopy > ...)
        {
            // ... do some work with someNumberCopy
        }
        else
        {
            // ... do something else with someNumberCopy
        }
    }
}

制作实例变量的副本有什么好处吗？