define crowdsourcing

What are the advantages of using an array to define constants? in this post, we finally edited tp_2015_1 from 2015-05-2221:29:28 to see how to define constants using arrays in the graph. I always feel so much trouble, why don't I write a constant directly, such as define (ATTACH_MALBUM, shopmember)? How good is it, but it's hard to get the whole array. what is th

You can use macros to define "functions" without return values ". For example: # Define printmax (A, B)/do/{/INT x = A, y = B;/printf ("MAX: % d/N", x> Y? X: Y); //} while (0) //... printmax (3, 4 ); Such a "function" is essentially different from a function in the true sense, because a macro is a pre-compilation behavior and only replaces the text before compilation. In Python source code, we often see

define the best Cache-control policy Follow the decision tree above to determine the best cache policy for the specific resource or set of resources your app uses. Ideally, your goal should be to cache as many responses as possible on the client, cache as long as possible, and provide a validation token for each response to enable efficient re-validation. Cache-control Instructions and instructions max-age=

1. Custom Constants * Must be defined with function define ()* The value can not be changed after the definition is finished* Use the constant name directly, not as a variable in front plus $sFor example: Define ("PI", 3.14); Define a constant$area = Pi*r*r; Calculate the area of a circleDefine ("URL", "http://www.jb51.net");echo "My URL is:". URL; 2 System con

#define是C的指令, used to define aliases for various data types, similar to TypeDef, but with a few different1,typedef is limited to defining a symbol name for a type, and # define can define not only the symbol name for the type, but also the alias for the value, such as 1 to true;The 2,typedef is interpreted by the compi

If you want to learn ExtJS well, it is necessary for JavaScript, that is, understanding the ExtJS underlying infrastructure. So now we're going to start learning the EXTJS infrastructure. How to create an ext class, create a complex flow of classes -Deep analysis of ext.js and Ext-more.js -Ext extensions to native JavaScript classes -EXT Operations DOM -Ext starts responding to events ways to define classes: DefineFor the ext4.x version, the

Recently a product debugging found a problem, together to check a small partner's C program. The problem is not big, but it exposes a little problem. For example: portb=0x23; He means to place the 5th and 2nd digits 1, but can you see the 5th and 2nd position 1? In fact, it should be 0x24, he did not find this error, calculated wrong, so the correct is: portb=0x23; In fact, we can completely avoid this mistake. Open our compiler's own header file, such as the AVR TINY13 header file has the follo

dbus_glib _ $ (prefix) _ object_info. The header file wei_server.h is generated as follows: /* Generated by using-binding-tool; do not edit! */ # Ifndef _ dbus_glib_marshal_com_wei_MARSHAL_H __ # Define _ dbus_glib_marshal_com_wei_MARSHAL_H __ # Include G_BEGIN_DECLS # Ifdef G_ENABLE_DEBUG # Define g_marshal_value_peek_boolean (v) g_value_get_boolean (v) #

Brief introductionThis article is intended to describe how to define a Python source file encoding. The Python interpreter can parse the current file based on the encoding information specified. Typically, this approach improves the parser's recognition of Unicode-encoded source files and supports writing Unicode encodings, such as using UTF-8 in an editor that supports Unicode encoding.ProblemIn python2.1, Unicode encoding can only be achieved by mea

Define variables in the C header file and variables in the C Language I recently looked at a PHP extension source code and encountered a problem during compilation: ld: 1 duplicate symbol for architecture x86_64 After carefully reading the source code, we found that the definition of global variables appeared in the header file. ZEND_DECLARE_MODULE_GLOBALS(xx) Easy to understand // t1.h#ifndef T1_H#define T

#define aspect_ratio=1.1Const Double aspectratio=1.11. Using a macro causes the preprocessor to unconditionally replace the Aspect_ratio in the program code with 1.1, the compiler has never seen Aspect_ratio, debug compilation can be difficult to track, and the const constant resolves the problem.2. The scope of the macro definition is the subsequent compilation process until it is #undef, so the macro definition cannot be used as an exclusive constan