identifier

How to call on a function found on another file?

由 我怕爱的太早我们不能终老 提交于 2019-11-26 11:59:46
问题 I\'m recently starting to pick up C++ and the SFML library, and I was wondering if I defined a Sprite on a file appropriately called \"player.cpp\" how would I call it on my main loop located at \"main.cpp\"? Here is my code (Be aware that this is SFML 2.0, not 1.6!). main.cpp #include \"stdafx.h\" #include <SFML/Graphics.hpp> #include \"player.cpp\" int main() { sf::RenderWindow window(sf::VideoMode(800, 600), \"Skylords - Alpha v1\"); while (window.isOpen()) { sf::Event event; while (window

Are python variables pointers? or else what are they?

由 拈花ヽ惹草 提交于 2019-11-26 11:12:24
Variables in Python are just pointers, as far as I know. Based on this rule, I can assume that the result for this code snippet: i = 5 j = i j = 3 print(i) would be 3 . But I got an unexpected result for me, it was 5 . Moreover, my Python book does cover this example: i = [1,2,3] j = i i[0] = 5 print(j) the result would be [5,2,3] . What am I understanding wrong? We call them references. They work like this i = 5 # create int(5) instance, bind it to i j = i # bind j to the same int as i j = 3 # create int(3) instance, bind it to j print i # i still bound to the int(5), j bound to the int(3)

Unicode identifiers in Python?

由 烈酒焚心 提交于 2019-11-26 09:30:52
问题 I want to build a Python function that calculates, and would like to name my summation function Σ. In a similar fashion, would like to use Π for product, and so on. I was wondering if there was a way to name a python function in this fashion? def Σ (..): .. .. That is, does Python support unicode identifiers, and if so, could someone provide an example for it? Thanks! Original motivation for this was a piece of Clojure code I saw today that looks like, (defn entropy [X] (* -1 (Σ [i X] (* (p i

How to use EL with <ui:repeat var> in id attribute of a JSF component

由 我与影子孤独终老i 提交于 2019-11-26 08:47:16
I have following code: <ui:repeat var="class2" value="#{bean.list}" varStatus="status"> <h:form id="#{class2.name}"> <h:outputText value="#{class2.name}" /> </h:form> </ui:repeat> However, when I open the page, it errors as follows: component identifier must not be a zero-length String But it is properly printed in the <h:outputText> . How is this caused and how can I solve it? BalusC You can use EL in the id attribute of a JSF component, but the EL variable has to be available during view build time , while the JSF component tree is to be built. However, the <ui:repeat> runs during view

Cannot create a database table named &#39;user&#39; in PostgreSQL

由 穿精又带淫゛_ 提交于 2019-11-26 04:52:20
问题 It seems PostgreSQL does not allow to create a database table named \'user\'. But MySQL will allow to create such a table. Is that because it is a key word? But Hibernate cannot identify any issue (even if we set the PostgreSQLDialect). 回答1: user is a reserved word and it's usually not a good idea use reserved words for identifiers (tables, columns). If you insist on doing that you have to put the table name in double quotes: create table "user" (...); But then you always need to use double

Using number as “index” (JSON)

由 放肆的年华 提交于 2019-11-26 04:26:51
问题 Recently started digging in to JSON, and I\'m currently trying to use a number as \"identifier\", which doesn\'t work out too well. foo:\"bar\" works fine, while 0:\"bar\" doesn\'t. var Game = { status: [ { 0:\"val\", 1:\"val\", 2:\"val\" }, { 0:\"val\", 1:\"val\", 2:\"val\" } ] } alert(Game.status[0].0); Is there any way to do it the following way? Something like Game.status[0].0 Would make my life way easier. Of course there\'s other ways around it, but this way is preferred. 回答1: JSON only

identify groups of linked episodes which chain together

由 白昼怎懂夜的黑 提交于 2019-11-26 04:01:40
问题 Take this simple data frame of linked ids: test <- data.frame(id1=c(10,10,1,1,24,8),id2=c(1,36,24,45,300,11)) > test id1 id2 1 10 1 2 10 36 3 1 24 4 1 45 5 24 300 6 8 11 I now want to group together all the ids which link. By \'link\', I mean follow through the chain of links so that all ids in one group are labelled together. A kind of branching structure. i.e: Group 1 10 --> 1, 1 --> (24,45) 24 --> 300 300 --> NULL 45 --> NULL 10 --> 36, 36 --> NULL, Final group members: 10,1,24,36,45,300

dollar sign in variable name?

由 女生的网名这么多〃 提交于 2019-11-26 03:59:42
问题 I stumbled on some C++ code like this: int $T$S; First I thought that it was some sort of PHP code or something wrongly pasted in there but it compiles and runs nicely (on MSVC 2008). What kind of characters are valid for variables in C++ and are there any other weird characters you can use? 回答1: The only legal characters according to the standard are alphanumerics and the underscore. The standard does require that just about anything Unicode considers alphabetic is acceptable (but only as

How to use EL with <ui:repeat var> in id attribute of a JSF component

由 坚强是说给别人听的谎言 提交于 2019-11-26 02:00:50
问题 I have following code: <ui:repeat var=\"class2\" value=\"#{bean.list}\" varStatus=\"status\"> <h:form id=\"#{class2.name}\"> <h:outputText value=\"#{class2.name}\" /> </h:form> </ui:repeat> However, when I open the page, it errors as follows: component identifier must not be a zero-length String But it is properly printed in the <h:outputText> . How is this caused and how can I solve it? 回答1: You can use EL in the id attribute of a JSF component, but the EL variable has to be available during

Are python variables pointers? or else what are they?

由 橙三吉。 提交于 2019-11-26 01:58:02
问题 Variables in Python are just pointers, as far as I know. Based on this rule, I can assume that the result for this code snippet: i = 5 j = i j = 3 print(i) would be 3 . But I got an unexpected result for me, it was 5 . Moreover, my Python book does cover this example: i = [1,2,3] j = i i[0] = 5 print(j) the result would be [5,2,3] . What am I understanding wrong? 回答1: We call them references. They work like this i = 5 # create int(5) instance, bind it to i j = i # bind j to the same int as i
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