increment

问题 When I try to write a postfix/prefix in/decrement, followed by a post/prefix in/decrement, I get the following error: Invalid argument to operation ++/-- . But, according to JLS: PostIncrementExpression: PostfixExpression ++ and PostfixExpression: Primary ExpressionName PostIncrementExpression PostDecrementExpression so writing: PostfixExpression ++ ++ should be possible... Any thoughts? 回答1: Note that the raw grammar lacks any semantics. It's just syntax, and not every syntactically valid

问题 I have a JSON file that looks like this: "Algeriet" : [ { "name" : "Nyårsdagen", "date" : "2013-01-01", "ID" : "1" }, { "name" : "Mawlid En Nabaoui Echarif", "date" : "2013-01-24", "ID" : "2" }, { "name" : "Första maj", "date" : "2013-05-01", "ID" : "3" }, ... ] Now I would like to begin incrementing the IDs from 0 instead of 1. How can I do this with Sublime Text 2? I have installed the Text Pastry plugin but I'm not sure how to select the IDs in the text so that I can replace these values.

问题 I need help in writing a query in Oracle for the following data. The data is sorted by Person and Day fields. Person Day Flag ------ --- ---- person1 day1 Y person1 day2 Y person1 day3 Y person1 day4 N person1 day5 N person1 day6 Y person1 day7 Y person1 day8 Y I need to have a Group_Number column that gets incremented whenever the Flag value changes. My result should look as below Person Day Flag Group_Number ------ --- ---- ------------ person1 day1 Y 1 person1 day2 Y 1 person1 day3 Y 1

问题 This question already has answers here : What's the best way to implement `next` and `previous` on an enum type? (2 answers) Closed 6 years ago . Is it possible to implement the ++ operator for an enum? I handle the current state of a state machine with an enum and it would be nice to be able to use the ++ operator. 回答1: You can't "increment" an enum, but you can get the next enum: // MyEnum e; MyEnum next = MyEnum.values()[e.ordinal() + 1]; But better would be to create an instance method on

问题 can anyone tell me what is the process of i+++ increment in c++. 回答1: It is a syntax error. Using the maximum munching rule i+++ is tokenized as: i ++ + The last + is a binary addition operator. But clearly it does not have two operands which results in parser error. EDIT: Question from the comment: Can we have i++++j ? It is tokenized as: i ++ ++ j which again is a syntax error as ++ is a unary operator. On similar lines i+++++j is tokenized by the scanner as: i++ ++ + j which is same as ((i

问题 In a loop in C++, I usually encounter situations to use ++ or +=1 , but I can't tell their difference. For instance, if I have an integer int num = 0; and then in a loop I do: num ++; or num += 1; they both increase the value of num , but what is their difference? I doubt num++ could work faster than num+=1 , but how? Is this difference subtle enough to be ignored? 回答1: num += 1 is rather equivalent to ++num . All those expressions ( num += 1 , num++ and ++num ) increment the value of num by

问题 In a loop in C++, I usually encounter situations to use ++ or +=1 , but I can't tell their difference. For instance, if I have an integer int num = 0; and then in a loop I do: num ++; or num += 1; they both increase the value of num , but what is their difference? I doubt num++ could work faster than num+=1 , but how? Is this difference subtle enough to be ignored? 回答1: num += 1 is rather equivalent to ++num . All those expressions ( num += 1 , num++ and ++num ) increment the value of num by

问题 I'm new to Python, coming from Java and C. How can I increment a char? In Java or C, chars and ints are practically interchangeable, and in certain loops, it's very useful to me to be able to do increment chars, and index arrays by chars. How can I do this in Python? It's bad enough not having a traditional for(;;) looper - is there any way I can achieve what I want to achieve without having to rethink my entire strategy? 回答1: In Python 2.x, just use the ord and chr functions: >>> ord('c') 99

问题 This question already has answers here : Why doesn't the post increment operator work on a method that returns an int? (11 answers) Closed last year . private void calculateForEachQuestion() { ... if (questions.size() >= answers.size()) { answers.forEach(answer -> { if (questions.contains(answer)) this.answer.setPoints((this.answer.getPoints())++); // Variable expected ^ }); } The error I encountered is: unexpected type required: variable found: value What is wrong with the statement? this

问题 I have a single table containing many users. In that table I have column called user_id (INT), which I want increment separately for each person. user_id MUST start at 1 I've prepared a simple example: Showing all names +--------------+-----------------------+ | user_id | name | +--------------+-----------------------+ | 1 | Bob | | 1 | Marry | | 2 | Bob | | 1 | John | | 3 | Bob | | 2 | Marry | +--------------+-----------------------+ Showing only where name = Bob +--------------+------------