variables

问题 I was looking into this issue but I couldn't find any solid answers for this specific purpose. Let's say I have a URL of... http://mysite.com/stuff/index.php?search=my+search How can I grab this URL and remove index.php?search=my+search from it so it would just be http://mysite.com/stuff/ ? Basically I just want to grab the parent URL without a filename or get variables... No matter what the URL (so I don't have to customize the function for every page I want to use it on) So for an

问题 I am a C++ programmer starting with PHP. I find that I lose most of the debugging time (and my selfesteem!) due to undefined variables. From what I know, the only way to deal with them is to watch the output at execution time. Are other strategies to notice these faults earlier (something like with C++ that a single compile gives you all the clues you need)? 回答1: This is a common complaint with PHP. Here are some ideas: Use a code analysis tool. Many IDEs such as NetBeans will help also. Just

问题 I'm looking for a way to combine jquery variables. Looking through related questions, nobody seems to be trying what I want to do. $("body, div, p") is one method of combining by selectors, but after you assign a selector to a variable, how do you combine them in a similar fashion? Here is one method I tried, but did not get it to work. I also tried putting them into an array (by simply adding brackets before $body and after $p). $body = $("body"); $div = $("div"); $p = $("p"); $mixed = $(

问题 I'm looking for a way to combine jquery variables. Looking through related questions, nobody seems to be trying what I want to do. $("body, div, p") is one method of combining by selectors, but after you assign a selector to a variable, how do you combine them in a similar fashion? Here is one method I tried, but did not get it to work. I also tried putting them into an array (by simply adding brackets before $body and after $p). $body = $("body"); $div = $("div"); $p = $("p"); $mixed = $(

问题 Where does the identifiers or variable name gets stored in java? I understand that objects get stored in heap and variable gets store in heap or stack depending on the type and scope of variable. Can we debug or write any program to confirm it? Thanks & Regards 回答1: Names of fields are stored as part of the class metadata, in formerly-PermGen now-Metaspace. Array elements don't have names, only numbers. (Cue Patrick McGoohan.) Names of method and constructor parameters and local variables and

问题 In trying to test whether a variable has been defined, I discovered that the IF, IFNULL, and COALESCE statements return simply BLOB rather than the value I expected when (a) the variable has not been defined or (b) it has been explicitly set to NULL before being assigned a value in the session. I've verified this in MySQL versions 5.7 and 8.0. SELECT IF(@p IS NULL, 'is null', 'not null'); # 'is null' SELECT IF(@p IS NULL, 'is null', @p); # BLOB SELECT IFNULL(@p, 'is null'); # BLOB SELECT

问题 I need to execute from mysql shell an SQL file based on a condition like mysql> source @var where @var contains the filename 回答1: This is not possible. source is a command that is recognized and executed locally by the MySQL client program. Variables exist on the server, so the client has no idea what @variable means. 来源： https://stackoverflow.com/questions/1638654/how-do-i-use-mysql-source-command-with-a-mysql-variable

问题 This question already has answers here : What is this kind of assignment in Python called? a = b = True (4 answers) Closed 5 years ago . I am quite confused, consecutive equal = can be used in python like: a = b = c What is this language feature called? Is there something I can read about that? Can it be generated into 4 equals? a = b = c = d 回答1: This is just a way to declare a and b as equal to c . >>> c=2 >>> a=b=c >>> a 2 >>> b 2 >>> c 2 So you can use as much as you want: >>> i=7 >>> a=b

问题 Dart docs read: If you never intend to change a variable, use final or const, either instead of var or in addition to a type. A final variable can be set only once; Ok, this means that assigning a final variable second time will not work, but nothing is said about modifying, i.e. void main() { final List<int> list = [1,2,3]; list = [10, 9, 8]; //error! list ..clear() ..addAll([10, 9, 8]); //works! } As one can see, in essence, I re- assigned final variable list . Doesn't it contradict the

问题 I was reading 'Pointers on C' by Kenneth Reek and saw this line: A structure variable is a scalar, so you can perform the same kinds of operations with it that you can with other scalars. So what does it mean? I found a similar question on SO but it was related to some other language (I guess SQL) Thank you. 回答1: Section 6.2.5 of the C11 standard explains: Arithmetic types and pointer types are collectively called scalar types. Array and structure types are collectively called aggregate types