increment

问题 In a single-threaded application I use code like this: Interface function GetNextUID : integer; Implementation function GetNextUID : integer; const cUID : integer = 0; begin inc( cUID ); result := cUID; end; This could of course be implemented as a singleton object, etc. - I'm just giving the simplest possible example. Q: How can I modify this function (or design a class) to achieve the same result safely from concurrent threads? 回答1: You can use the Interlocked* functions: function

问题 I was having a conversation about the prefix increment operator, and we seem to have run into a disagreement. When running this code: var x = 0; x = ++x; is the second line equivalent to: x = (x = x + 1) OR x = (x + 1) It is hard to tell the difference because the results are identical (both result in x having a value of 1) I believe that the value is not saved to the original variable when the left hand side of the assignment is the variable itself. My counterpart disagrees and thinks the

问题 I would like to generate a vector based on repeating the string "FST" but with a number at the end which increments: "Fst1" "Fst2" "Fst3" "Fst4" ... "Fst100" 回答1: An alternative to paste is sprintf , which can be a bit more convenient if, for instance, you wanted to "pad" your digits with leading zeroes. Here's an example: sprintf("Fst%d", 1:10) ## No padding # [1] "Fst1" "Fst2" "Fst3" "Fst4" "Fst5" # [6] "Fst6" "Fst7" "Fst8" "Fst9" "Fst10" sprintf("Fst%02d", 1:10) ## Pads anything less than

问题 I have a quick question, which is probably easy to answer. I've goolged around, but not sure if I am searching correctly or what. Anyway, using PHP, how can I increment by halves? For example, I know I can use the following loop: <?php for ($i=1; $i<21; $i++) { print($i); } And it will print 1 - 20. But, how can I get it to output something like the following: 1 1.5 2 2.5 etc... Sorry for my ignorance on this, I'm just not sure how to go about it. Thanks! 回答1: Change $i++ to $i += 0.5 . Also,

问题 I have a quick question, which is probably easy to answer. I've goolged around, but not sure if I am searching correctly or what. Anyway, using PHP, how can I increment by halves? For example, I know I can use the following loop: <?php for ($i=1; $i<21; $i++) { print($i); } And it will print 1 - 20. But, how can I get it to output something like the following: 1 1.5 2 2.5 etc... Sorry for my ignorance on this, I'm just not sure how to go about it. Thanks! 回答1: Change $i++ to $i += 0.5 . Also,

问题 I need to make a 40 digit counter variable. It should begin as 0000000000000000000000000000000000000001 and increment to 0000000000000000000000000000000000000002 When I use the int class, it cuts off all the zeros. Problem is I need to increment the number and then convert it to a string, with the correct number of leading zeros. The total size should be 40 digits. So if I hit 50 for example, it should look like this: 0000000000000000000000000000000000000050 How can I do that and retain the

问题 The following is a simplified version of my code: <?php for($n=1; $n<=8; $n++): ?> <p><?php echo $n; ?></p> <p><?php echo $n; ?></p> <?php endfor; ?> I want the loop to run 8 times and I want the number in the first paragraph to increment by 1 with each loop, e.g. 1, 2, 3, 4, 5, 6, 7, 8 (this is obviously simple) However, I want the number in the second paragraph to increment by 2 with each loop, e.g... 1, 3, 5, 7, 9, 11, 13, 15 I can't figure out how to make the number in the second

问题 I wonder how C++ behaves in this case: char variable = 127; variable++; In this case, variable now equals to -128. However did the increment operator wrapped the value to its lower bound or did an overflow occurred? 回答1: An overflow occured and results in undefined behavior . Section 5.5: Ifduring the evaluation of an expression, the result is not mathematically defined or not in the range of representable values for its type , the behavior is undefined [...] The standard goes on to note that

问题 Is it possible from number type T to get number type Y that has value of T+1. type one = 1 type Increment<T extends number> = ??? type two = Increment<one> // 2 P.S. Currently, I have hardcoded interface of incremented values, but the problem is hardcoded and hence limited: export type IncrementMap = { 0: 1, 1: 2, 2: 3, 回答1: I would just hardcode it like this: type Increment<N extends number> = [ 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20, 21,22,23,24,25,26,27,28,29,30,31,32,33,34,35

问题 I'm having problems incrementing a counter under certain conditions. Input: <Users> <User> <id>1</id> <username>jack</username> </User> <User> <id>2</id> <username>bob</username> </User> <User> <id>3</id> <username>bob</username> </User> <User> <id>4</id> <username>jack</username> </User> </Users> Wanted Output: <Users> <User> <id>1</id> <username>jack01</username> </User> <User> <id>2</id> <username>bob01</username> </User> <User> <id>3</id> <username>bob02</username> </User> <User> <id>4<