php pi constant

The constant used to learn php at the front end and the constant used to learn php* Directory [1] definition constant [2] constant detection [3] system constant [4] before magic constant Constants do not exist in javascript. in php, they are

Php constants. Naming rules for constants: the same naming rules as variables: define () function format: define (constant name, value); example: define (PI, 3.14 ); constants and variables are the same: 1: naming rules for naming constants Naming:

PHP constant knowledge sorting, php constant knowledge sorting Constants in PHP are divided into custom constants and system constants. Constant features: After setting, the constant value cannot be changed. The constant name does not need to

A constant in PHP object-oriented PHP5. In PHP5, constants defined by const are different from those defined by variables. you do not need to add a $ modifier. ConstPI3.14. The constant names defined by const are generally capitalized. in PHP5, the

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

PHP constant definitions and value constants are assigned when defined, cannot be changed, cannot be destroyed, have super-global action, and constants can only store scalar data (character integer float);PHP Define ("Hello", "World");// variable

1 Simple Assignment1 // Preliminary simple to assign a constant value of 2 define('PI ', 3.14); 3 Echo PI2 Parametric analysisDefine (name, Value,bool)First parameter　　 Name constant names are generally named in uppercase. A second parametervalue

1. Structure and call (instantiation ): Class className {}, call: $ obj = new className (); when the class has a constructor, you should also input parameters. For example, $ obj = new className ($ v, $ v2 ...); 2. constructor and destructor:1.

I. Structure and call (instantiation): classclassName {}, call: $ obj = newclassName (); when a class has a constructor, you should also input parameters. For example, $ obj = newclassName ($ v, $ v2 & hellip;); 2: constructor and Destructor: 1.

1. Understanding PHP Code Identification It is very easy to write PHP code in the page, such as the following code: Just as you can write JavaScript scripting languages that need to be written between tags, you can write PHP code in the