class-constants

create an array of all constant of a class?

由 孤街浪徒 提交于 2020-02-01 05:16:26
问题 I was working with a class where almost 20 constant are defined, as i want all these constant value in an array, i just want to know is there any method which create an array of all constant of a class? I tried with compact BUT it does not work with constants. class Alpha { const ONE = 'fixone'; const TWO = 'fix_two'; const THREE = 3 public function __construct() { protected $arr_constant = compact(ONE,TWO,THREE); // gives FATAL Error // is there any method which collect all consant and

Can traits have properties & methods with private & protected visibility? Can traits have constructor, destructor & class-constants?

由 倾然丶 夕夏残阳落幕 提交于 2019-12-23 07:57:56
问题 I've never seen a single trait where properties and methods are private or protected. Every time I worked with traits I observed that all the properties and methods declared into any trait are always public only. Can traits have properties and methods with private and protected visibility too? If yes, how to access them inside a class/inside some other trait? If no, why? Can traits have constructor and destructor defined/declared within them? If yes, how to access them inside a class? If no,

Ruby “CONSTANTS” seem to be INVISIBLY ALTERABLE?

由 ぐ巨炮叔叔 提交于 2019-12-12 15:14:18
问题 I understand that "constants" in Ruby are by convention called constants but are in fact mutable. However I was under the impression that when they were "mutated" that there was a warning: class Z2 M = [0,1] end Z2::M # => [0, 1] Z2::M = [0,3] (irb):warning: already initialized constant Z2::M (irb):warning: previous definition of M was here However I found this is not the case all the time: a = Z2::M a[1] = 2 Z2::M # => [0,2] and no warning Is this a gap in the "warning" system? I am

Why constant data member of a class need to be initialized at the constructor?

由 牧云@^-^@ 提交于 2019-12-12 07:35:31
问题 I want to know why constant data member of a class need to be initialized at the constructor and why not somewhere else? What is the impact of doing so and not doing so? I also see that only static constant integral data can be initialized inside the class other than that non of the data members can be initialized inside the class. for eg:- Suppose below is my class declaration class A{ int a; // This we can initialize at the constructor or we can set this member by calling "vSet" member

Can I get CONST's defined on a PHP class?

由 徘徊边缘 提交于 2019-12-11 01:17:56
问题 I have several CONST's defined on some classes, and want to get a list of them. For example: class Profile { const LABEL_FIRST_NAME = "First Name"; const LABEL_LAST_NAME = "Last Name"; const LABEL_COMPANY_NAME = "Company"; } Is there any way to get a list of the CONST's defined on the Profile class? As far as I can tell, the closest option( get_defined_constants() ) won't do the trick. What I actually need is a list of the constant names - something like this: array('LABEL_FIRST_NAME', 'LABEL

Constant class members, assignment operator and QList

由 北城余情 提交于 2019-12-06 03:38:36
问题 Please conform if I am correct and tell me whether there is a better solution: I understand that objects with constant members like int const width; can not be handled by the synthetic assignment operator that is implicitly created by the compiler. But QList (and I suppose std::list, too) needs a working assignment operator. So when I want to use objects with constant members and QList I have three possibilities: Don't use constant members. (Not a solution) Implement my own assignment

Can I access a PHP Class Constant using a variable for the constant name?

由 非 Y 不嫁゛ 提交于 2019-12-05 13:03:35
问题 When accessing a class constant I see that I can use a variable for the class name, e.g. $classname::CONST_VALUE . What if I want to use a variable for the constant name, e.g. self::$constant . This does not seem to work. Is there a workaround? 回答1: $variable = $classname.'::'.$constant; constant($variable); See the docs: http://php.net/constant 来源： https://stackoverflow.com/questions/11717593/can-i-access-a-php-class-constant-using-a-variable-for-the-constant-name

create an array of all constant of a class?

由 淺唱寂寞╮ 提交于 2019-12-04 09:08:45
I was working with a class where almost 20 constant are defined, as i want all these constant value in an array, i just want to know is there any method which create an array of all constant of a class? I tried with compact BUT it does not work with constants. class Alpha { const ONE = 'fixone'; const TWO = 'fix_two'; const THREE = 3 public function __construct() { protected $arr_constant = compact(ONE,TWO,THREE); // gives FATAL Error // is there any method which collect all consant and create an array? protected $arr_contact = get_all_constant(__CLASS__); var_dump($arr_constant); } } $ref =

Constant class members, assignment operator and QList

由 ◇◆丶佛笑我妖孽 提交于 2019-12-04 07:38:57
Please conform if I am correct and tell me whether there is a better solution: I understand that objects with constant members like int const width; can not be handled by the synthetic assignment operator that is implicitly created by the compiler. But QList (and I suppose std::list, too) needs a working assignment operator. So when I want to use objects with constant members and QList I have three possibilities: Don't use constant members. (Not a solution) Implement my own assignment operator. Use some other container that does not need assignment operators Is that correct? Are there other

Can I access a PHP Class Constant using a variable for the constant name?

由 浪子不回头ぞ 提交于 2019-12-03 23:58:49
When accessing a class constant I see that I can use a variable for the class name, e.g. $classname::CONST_VALUE . What if I want to use a variable for the constant name, e.g. self::$constant . This does not seem to work. Is there a workaround? Summoner $variable = $classname.'::'.$constant; constant($variable); See the docs: http://php.net/constant 来源： https://stackoverflow.com/questions/11717593/can-i-access-a-php-class-constant-using-a-variable-for-the-constant-name
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