variables

问题 Why in Objective-C I can set instance variable inside a block: @interface CMVServices : UIViewController @property (nonatomic, strong) NSMutableArray *times; @implementation CMVServices @synthesize times=_times; and set the _times instance variable inside a block: (some code ) . . [query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) { [_times addObjectsFromArray:objects]; } but I can't in Swift? class ViewController: UIViewController var times :AnyObject[]! query

问题 Earlier today I asked for help for building a database in prolog and how to search by parameters, and somebody came up with this: You can also add a list of terms to every processor, like: processor(pentium_g4400, [brand('intel'), family('pentium'), series('g4400'), clock(3.3), socket('lga1151'), ram('ddr4'), cores(2), threads(2)]). In that case you can query with: processor(Proc, Specs), member(family('pentium'), Specs). And it worked pretty well, but, the command "member" does not seem to

问题 If I use a protected variable, does the variable exist for the whole web application or does it get removed when the user move to other page by get or post? I do know that it is not accessible in other pages unless I use static variable, but I am curious as to if it exists for the whole application. Please let me know! 回答1: when you move to other page and return, a new instance of your page class will be created and so all non static variables will be reset. The value will be valid in a one

问题 I need to concatenate two string variables and place the result back in the first variable. These two strings can contain any arbitrary characters, like newline, exclamation, etc. The main script runs with delayed expansion disabled , so I have to use SETLOCAL EnableDelayedExpansion for actual concatenation. I just don't know how to get the result back out of the local and into the global variable. I would like to avoid using temporary files. I wish batch files allowed delayed expansion

问题 I need to concatenate two string variables and place the result back in the first variable. These two strings can contain any arbitrary characters, like newline, exclamation, etc. The main script runs with delayed expansion disabled , so I have to use SETLOCAL EnableDelayedExpansion for actual concatenation. I just don't know how to get the result back out of the local and into the global variable. I would like to avoid using temporary files. I wish batch files allowed delayed expansion

问题 How can I set a variable's name with the value of another value in Twig? I would think that It would go something like this: {% set queCount = loop.index %} {% for row2 in answer+queCount %} But this does not work. Also making a string from that will break the loop (because it does not search for a string). I know how to do this in PHP so for clarification, this is what I would like to achieve: $count = 1; $args["answer$count"] which returns $args["answer1"] But this time, not with strings

问题 I am using session variables to control logins and page access. I use variables to control different user groups that a user belongs to, so I have quite a few session variables. I also use a session variable to remember the users last visited page upon refresh. When the user logs out, I use session_destroy(); to remove all variables. What i would like to do is to maintain the last visited page variable even after the user has logged out. I think I could do it by using the unset function on

问题 I currently have this for loop inside my template: {% for i in 1234|make_list %} I would like to obtain something like this inside loop: {{ form.answer_{{ i }} }} I am aware that the above line is not valid (it raises TemplateSyntaxError), but I would like to know if there is any way to use the value of i as part my other variable name. 回答1: First, you would need a custom template filter to mimic getattr() functionality, see: Performing a getattr() style lookup in a django template Then, you

问题 Let's say I have Freemarker variable A that contains the name of another variable on the hash tree, say. "B." I'd like to use a to read the value of B so, for example, if B contained "C" I could tell Freemarker to output C using A: ${${A}} should result in the output of "C". Naturally, this doesn't work in Freemarker, but is there a way to accomplish this? 回答1: Use the .vars special variable, which is a hash (map) of the variables, and hence you can use the aHash[aKeyExpression] syntax: ${

问题 What is the Oracle equivalent of this MS SQL Server notation? DECLARE @Variable INT SET @Variable = 1 回答1: In PL/SQL, you have a declare block: declare x integer := 1; ... begin ... end; If you are writing an SQL*Plus script, you use variable to declare a bind variable variable x integer := 1; It's also possible to define variables. 回答2: In PL/SQL: DECLARE a number; BEGIN a := 1; END; You can paste this code in SQLPlus to run it. 来源： https://stackoverflow.com/questions/2708888/create-variable