identifier

What is the meaning of leading underscores in a C++ constructor?

由 ε祈祈猫儿з 提交于 2019-12-10 13:41:26
问题 OK I am not a very experienced C++ programmer, but I was wondering what is the significance of the underscores in the arguments of the following constructor? class floatCoords { public: floatCoords(float _x, float _y, float _width, float _height) : x(_x), y(_y), width(_width), height(_height) { } float x, y, width, height; ... 回答1: It's just a convenient naming convention, it means nothing to the language. Just be sure you don't follow it with an upper-case letter: What does double underscore

MYSQL: Avoiding cartesian product of repeating records when self-joining

由 一笑奈何 提交于 2019-12-10 09:31:58
问题 There are two tables: table A and table B. They have the same columns and the data is practically identical . They both have auto-incremented IDs, the only difference between the two is that they have different IDs for the same records. Among the columns, there is an IDENTIFIER column which is not unique , i.e. there are (very few) records with the same IDENTIFIER in both tables. Now, in order to find a correspondence between the IDs of table A and the IDs of table B, I have to join these two

Non-ASCII Python identifiers and reflectivity [duplicate]

由 别说谁变了你拦得住时间么 提交于 2019-12-09 16:18:11
问题 This question already has answers here : Identifier normalization: Why is the micro sign converted into the Greek letter mu? (2 answers) Closed last year . I have learnt from PEP 3131 that non-ASCII identifiers were supported in Python, though it's not considered best practice. However, I get this strange behaviour, where my 𝜏 identifier (U+1D70F) seems to be automatically converted to τ (U+03C4). class Base(object): def __init__(self): self.𝜏 = 5 # defined with U+1D70F a = Base() print(a.𝜏)

C# Variable Name “_” (underscore) only

由 ☆樱花仙子☆ 提交于 2019-12-08 14:33:50
问题 I was just hit with a minor issue in C#, it was just a copy-paste mistake but don't know how C# accept it. This code gets compiled successfully...HOW namespace DemoNS { class DemoClass { String _ = new String('a', 1); } } Is there any default significance of variable named _ ? 回答1: No, there is no default significance, _ is just a variable name like any other. I like to use it in similar way to Prolog's anonymous variables: when you're creating a lambda that ignores one of its parameters, you

Multiple reuse identifiers in a UITableView

由 删除回忆录丶 提交于 2019-12-08 10:42:29
问题 I have a table view where the cells have a variable height. This causes problems with having a reuse identifier but I would really like the cache for UITableViewCells that Apple gave me. Therefore I tried making a variable reuse identifier and it seems but I'm not sure if it's the right way. Can anyone tell me if I'm handling multiple reuse identifiers right? - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { float height = [self

Class with no name

由 半腔热情 提交于 2019-12-06 11:03:11
问题 I read this about class in the C++ standard document: A class is a type. Its name becomes a class-name (9.1) within its scope. class-name: identifier template-id I found this grammar for an identifier in the C++ Standard: 2.10 Identifiers identifier: nondigit identifier nondigit identifier digit nondigit: one of universal-character-name _ a b c d e f g h i j k l m n o p q r s t u v w x y z A B C D E F G H I J K L M N O P Q R S T U V W X Y Z digit: one of 0 1 2 3 4 5 6 7 8 9 Now I tried doing

ZF2 - \Zend\Db\Adapter\Platform::getQuoteIdentifierSymbol()

由 烈酒焚心 提交于 2019-12-06 02:47:49
问题 Code is as following, where I aim to use Pdo_mysql: use \Zend\Db\Adapter\Adapter; use \Zend\Db\Sql\Sql; use \Zend\Db\Sql\Expression; $params = array( 'driver' => "Pdo_mysql", 'host' => &$this->Registry->config[ 'sql' ][ 'host' ], 'username' => &$this->Registry->config[ 'sql' ][ 'user' ], 'password' => &$this->Registry->config[ 'sql' ][ 'passwd' ], 'dbname' => &$this->Registry->config[ 'sql' ][ 'dbname' ] ); $this->adapter = new \Zend\Db\Adapter\Adapter( $params ); $this->platform = $this-

Javascript - Uncaught SyntaxError: Unexpected identifier

由 。_饼干妹妹 提交于 2019-12-05 22:37:44
问题 I'm having a frustrating time trying to get this to work, Chrome keeps displaying an Uncaught Syntax error, but being a beginner to javascript, I have no idea where to look. Any help or pointers would be appreciated function details(user) { var fuel = prompt("Would you prefer petrol or diesel?"); var passengers = prompt("How many passengers will there be?"); var aircon = prompt("Do you require air-conditioning?"); var transmission = prompt("Do you want a Manual, Semi-Automatic or Automatic

How many Product-ids to create for Subscription in iPhoneSDK

由 人盡茶涼 提交于 2019-12-05 20:39:29
For your information, I have already implemented In-app Purchase in the application and it is working fine with Content Hosting at Apple as well as Server Model .I have logic in my app to check whether user has already downloaded the content ,if not download it using NKIssue as it is Newsstand app. Here is the my requirement for Subscription : There is one issue of the magazine published each month. What I want is for users to subscribe i.e. for 3,6,12 months, and during this time, they receive one magazine issue each month as it is published. If they want to buy any of the previous issues,

What's the rationale/history for the # convention of identifying methods in Ruby?

由 旧巷老猫 提交于 2019-12-05 19:56:39
问题 For example, I've always seen methods referred to as String#split , but never String.split , which seems slightly more logical. Or maybe even String::split , because you could consider #split to be in the namespace of String . I've even seen the method alone, when the class is assumed/implied ( #split ). I understand that this is the way methods are identified in ri. Which came first? Is this to differentiate, for example, methods from fields? I've also heard that this helps differentiates
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