Numeric Constants
A numeric constant is what is commonly called a constant. In C + +, numeric constants are type-sensitive, and their types are recognized in literal form.
Type of integer constant (integer)As you know in the previous section:
C + + data typesthe object that the computer handles is the data, and the data is in a certain form (for example, integers, floating-point numbers, characters, etc.). There are often some links between different data (for example, a number of
Constant
It is often found that the code contains some constant values that recur over and over again. You can also find that your code uses numbers that are hard to remember, and those numbers don't have a clear meaning.In these cases, the
3.2.2 Constantsand variables can be used in the program to express those that may change the amount of data corresponding to, in C + +, we use constants to express those always remain unchanged data volume. In simple terms, the values, characters,
3.2.2 Constantsand variables can be used in the program to express those that may change the amount of data corresponding to, in C + +, we use constants to express those always remain unchanged data volume. In simple terms, the values, characters,
Use of custom constants and system constants of ThinkPHP. We all know that ThinkPHP's custom constants and the constants used by system constants define a constant volume. in php, the constant definition rule is define (constant name, "constant ");
This section describes the introduction of include, include_oncerequire, and require_once constants to the file and constants. in the previous article, we discussed the application of functions, but it is only used to call functions in a file. when
Tips"Effective Java, third Edition" an English version has been published, the second edition of this book presumably many people have read, known as one of the four major Java books, but the second edition of 2009 published, to now nearly 8 years,
(1) different compiler processing methodsDefine macros are expanded during the preprocessing phase.Const constants are used during the compile run phase.(2) Different types and security checksDefine macros have no type, do not do any type checking,
This article through the PHP source code, starting from the structure of static variables, constants, magic constants analysis.
1. Static variablesAs we all know, static variables are loaded when the PHP script loads, That is 1. The object can be
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