define must have

There are many places in the C language where macro definitions are used, such as in header files to prevent header files from being repeatedly included: #ifndef ctest_header_h #define CTEST_HEADER_H /header file content #endif Many macro

Yesterday encountered a problem, pycharm can not run the Django program, see the error is: django.core.exceptions.ImproperlyConfigured:Requested setting CACHES, but Settings is not configured. You must either define the environment variable

I know, some people (such as before I) write JS for the For loop, are not used to add Var, which is of course allowed by the syntax. For example, below.For (i=0; I; I+ +) {// will not be written: Var i=0alert (i);}However, this is really not a good

Your project does not have a test pass may be the cause of your project-because the class of your project Intermediate association involves too manyOwn project "Such a configuration error"@OneToMany (Fetch=fetchtype.lazy,cascade =

When a subclass inherits the parent class, if the parent class does not have a constructor that defines the parameter, the subclass can inherit the default constructor of the parent classWhen a constructed method with parameters is defined in the

Let's look at a few examples (1) struct{int x; int y;} Test1; Well, define the structure test1, test1.x and test1.y can be used in the statement. (2) struct test {int x; int y;} Test1; Well, define the structure test1, test1.x and test1.y can be

# Define is a macro definition Command provided in C language. Its main purpose is to provide programmers with some convenience in programming and improve the program running efficiency to a certain extent, however, students often

The Define () function defines a constant.define () functions: Defines a constant. Constants is much like variables, except for the following differences: constants [constant] and variables [variable] There are many similarities, so it is easy to

For a long time, macro definition # define is used to define some simple constants. At most, it is used to define a function. It seldom pays attention to macro definition usage. Until the following code is displayed: #define PLAYSOUNDEFFECT(...) \[[

Macro definition in C # define usage, # Define is a macro definition Command provided in C language. Its main purpose is to provide programmers with some convenience in programming and improve the program running efficiency to a certain extent,