python class constants

(): g_num1 = 10 result = g_num1 + 2 print ("result: % d" % result) before the add_num () function call) other () #################### result: 12 # result: 4 # result: 2 # g_num1: 3 # g_num2: 5 #################### Access global variables in file 2. # FileName: file2import file1file1. add_num () # g_num1 changed to test = file1.g _ num1 + 1 print ("test: % d" % test) Avoid using global variables whenever possible. Different modules can freely access global variables, which may lead to unpredic

1. Custom Constants the value of a constant can only be scalar data ( Boolean , integer , float and the string ) or null . Once a constant is defined, it cannot be redefined or undefined. There are two ways of defining this: with define () function to define constants Define (' STATUS ', 3); Case is not sensitive if the third argument is set to True Echo STATUS; with Const keyword to defin

Php customizes global constants and class constants/*** 1. define (name, value, case_insensitive) customizes global constants. the default value is case sensitive. * 2. const defines class constants. * 3. do not use "$" * 4. do no

Php customizes global constants and class constants *** 1. define (name, value, case_insensitive) customizes global constants. the default value is case sensitive. * 2. const defines class constants. * 3. do not use "$" * 4 before

/** * 1, define (name,value,case_insensitive) custom global constants, default case Sensitive * 2, Const defines class constants. * 3, the constant name do not use "$" * 4, the name of the constant all use uppercase letters. *///defines global constants Languagedefine (' LANGUAGE ', ' China '); Echo language;//language

PHP Custom Global constants and class constants

another type, or some other fallback (dependent operator).See for details [Implementing arithmetic operations][3] ellipsis Most of this special value is used to combine slice syntax that is extended for user-defined container data types. __debug__ This constant is true if Python is not started with AN-O option. Also the Assert statement.If Python does not start with the-o option, the constant is true, see

members, using classes to access static members "so that the individual accessors are also easy to distinguish""At the business logic level, it is possible to differentiate whether it is a static method: The method uses a non-static method if it is a certain instance object. If the method applies to all objects, set the method to a static method. 】Although a non-static method is also an object reference to the encoding area for execution, $this in the method can specify the object for operation

for first, and then the attribute is searched layer by level, which is the problem that needs attention."The overriding mechanism created by the inheritance chain is to ensure the priority of access and to ensure the personalization of subclasses""It is also important to note that in the overriding mechanism of inheritance, a property cannot be lower than the parent's original property (that is, if the parent class uses public, the subclass can only

specifications, so that other programmers to achieve 2, when multiple peer class, all need to implement a function, but the way to achieve different; Summary: 1, the interface can not be instantiated, all the methods in the interface can not have the main; 2. A class can implement multiple interfaces, separating class demo implements if1,if2,if3{} with commas (

;start ();$p =new Phone ();$p->start (); When to use the interface:1, set specifications, let other programmers to achieve2, when a number of peer class, all need to implement a function, but the way of implementation is different;Summary:1, the interface can not be instantiated, the interface of all methods can not have the subject;2, a class can implement multiple interfaces, separated by a comma

, but the way of implementation is different; Summary: 1, the interface can not be instantiated, the interface of all methods can not have the subject; 2, a class can implement multiple interfaces, separated by a comma (,) class demo implements if1,if2,if3{} 3, the interface can have attributes, but must be constants, consta