identifier

问题 I am actually creating an iOS app, and want to store some details about Photo Library pictures in an SQLite database. I also would like to be able to share this data across the different devices the user has (imagine someone wanted to reorganize pictures on his iPhone, and wants to retrieve the same order in his iPad). I have searched across the Apple documentation, but did not find any PHAsset identifier that is shared across devices. I also tried to check if the PHImageFileURLKey ,

问题 CSS 2.1 defines identifiers as In CSS, identifiers can contain only the characters [a-zA-Z0-9] and ISO 10646 characters U+00A0 and higher, plus the hyphen (-) and the underscore (_); they cannot start with a digit, two hyphens, or a hyphen followed by a digit. Identifiers can also contain escaped characters and any ISO 10646 character as a numeric code. Therefore, -- should be an invalid identifier, and thus #-- shouldn't select the element with id="--" : body { color: black } #-- { color:

问题 I set the table CREATE TABLE author ( id serial NOT NULL, name character varying(255) NOT NULL, orcid character varying(128) NOT NULL, "position" integer NOT NULL, CONSTRAINT author_pkey PRIMARY KEY (id ) ); Why does the "position" name contain "" ? How can I remove "" from position ? 回答1: Actually, position is non-reserved (cannot be function or type) I am referring to the list of reserved words in the manual. What you see is most probably the output of pgAdmin (which you should have

问题 I keep on getting the error identifier expected. I am still learning how to call classes and I believe I am doing it wrong. 回答1: You can't just put code inside a class - you need to put it in a method: public class OptionFrame { public void someMethod() { System.out.println ("It works"); } } ... or a constructor: public class OptionFrame { public OptionFrame() { System.out.println ("It works"); } } ... or even a static block: public class OptionFrame { static { System.out.println ("It works")

问题 I have a combined grammar where I need to provide for two identifier lexer rules. Both identifiers can be used at the same time. Identifier1 comes before Identifer2 in grammar. First identifier is static, whereas second identifier rule changes on the basis of some flag.(Using predicate). I want the second identifier to match in parser rules. But as both identifiers may match some common inputs, It does not fall on identifer2. I have created small grammar to make it understandable. Grammar is

问题 I've got a name clash between two different Haskell modules that want to use the same infix operator ( <*> ). The Haskell 98 report says that modid.varsym is permitted, but I can't get it to work. In their entirety here are Test.hs : module Test where import qualified Test2 as T three = T.<*> and Test2.hs : module Test2 where (<*>) = 3 But trying to compile results in an error message: Test.hs:6:12: parse error on input `T.<*>' I tried T.(<*>) but that doesn't work either. How can I refer to

问题 What is the difference between static global and non- static global identifier in C++? 回答1: Static limits the scope of the variable to the same translation unit . A static global variable has internal linkage . A non-static global variable has external linkage . Good Read: What is external linkage and internal linkage? 回答2: A global static variable is only available in the translation unit (i.e. source file) the variable is in. A non-static global variable can be referenced from other source

问题 The whole program is supposed to enter a combination lock and accept the combo. This is the code I'm having issues with. import java.util.*; // needed for Scanner public class CombinationLock extends Lock { // Instance Variables private String combination; Scanner keyboard = new Scanner(System.in); System.out.println("Enter Combination --> "); String combo = keyboard.nextLine(); if(combination = combo) { super.open(); } public String toString() { String str = super.toString() + "\n" +

问题 Updated Question What, exactly, qualifies as a valid property name in Javascript? How do various methods of property assignment differ? And how does the property name affect property access? Note The answers to my original question (seen below) helped to clear some things up, but also opened a new can of worms. Now that I've had a chance to become a bit more familiar with JavaScript, I believe I've been able to figure a lot of it out. Since I had a hard time finding this information

问题 Updated Question What, exactly, qualifies as a valid property name in Javascript? How do various methods of property assignment differ? And how does the property name affect property access? Note The answers to my original question (seen below) helped to clear some things up, but also opened a new can of worms. Now that I've had a chance to become a bit more familiar with JavaScript, I believe I've been able to figure a lot of it out. Since I had a hard time finding this information