while-loop

问题 Of course this is an impossible statement in java (to-date), however ideally I would like to implement it as it is at the heart of many iterations. For example the first multiple times it is called I'm doing it 650,000+ times when it is creating the ArrayList . Unfortunately the reality is that my actual code does not have the set inside the else loop; thus it will pass over both the add and then the set commands and wasting time. After that I have it also in another loop where it is only

问题 Of course this is an impossible statement in java (to-date), however ideally I would like to implement it as it is at the heart of many iterations. For example the first multiple times it is called I'm doing it 650,000+ times when it is creating the ArrayList . Unfortunately the reality is that my actual code does not have the set inside the else loop; thus it will pass over both the add and then the set commands and wasting time. After that I have it also in another loop where it is only

问题 This question already has answers here : How can I abort a running JDBC transaction? (4 answers) Closed 2 years ago . I have a program that continually polls the database for change in value of some field. It runs in the background and currently uses a while(true) and a sleep() method to set the interval. I am wondering if this is a good practice? And, what could be a more efficient way to implement this? The program is meant to run at all times. Consequently, the only way to stop the program

问题 This question already has answers here : How can I abort a running JDBC transaction? (4 answers) Closed 2 years ago . I have a program that continually polls the database for change in value of some field. It runs in the background and currently uses a while(true) and a sleep() method to set the interval. I am wondering if this is a good practice? And, what could be a more efficient way to implement this? The program is meant to run at all times. Consequently, the only way to stop the program

问题 If I am fetching data from a MySQL database and using a while loop to iterate through the data how would I add each one to array? $result = mysql_query("SELECT * FROM `Departments`"); while($row = mysql_fetch_assoc($result)) { } 回答1: Build an array up as you iterate with the while loop. $result = mysql_query("SELECT * FROM `Departments`"); $results = array(); while($row = mysql_fetch_assoc($result)) { $results[] = $row; } Alternatively, if you used PDO, you could do this automatically. 回答2:

问题 There are a number of different way to accomplish the same simple loop though the items of an object in c#. This has made me wonder if there is any reason be it performance or ease of use, as to use on over the other. Or is it just down to personal preference. Take a simple object var myList = List<MyObject>; Lets assume the object is filled and we want to iterate over the items. Method 1. foreach(var item in myList) { //Do stuff } Method 2 myList.Foreach(ml => { //Do stuff }); Method 3 while

问题 I use opencsv to parse csv files, and my code is while( (line = reader.readNext()) != null ) { .... } I got a compiler warning saying: comparing values of types Unit and Null using `!=' will always yield true [warn] while( (aLine = reader.readNext()) != null ) { How should I do the while loop? 回答1: In your case (line = reader.readNext()) is a functional literal that returns type Unit. You may rewrite the code as follows: while( {line = reader.readNext(); line!= null} ) { .... } 回答2: An

问题 This question already has answers here : Shell script while read line loop stops after the first line (3 answers) Closed 8 months ago . I run the following bash script to rotate my mobile phone vids while read filename ; do nf=$(echo $filename |rev | cut -f1 -d '/'|cut -f2- -d '.' |rev) echo $nf rm -f ffmpeg2pass-0.log rm -f rotate/tmp.avi ffmpeg -i $filename -c:v libxvid -pass 1 -c:a libmp3lame -qscale:a 4 -vf "transpose=2,transpose=2" "rotate/tmp.avi" ffmpeg -i $filename -c:v libxvid -pass

问题 I'm writing a spellchecking program that will compare a user's text file with a dictionary to see if the words they entered are in the dictionary. If not, an error message is printed to tell the user that the specific word is wrong. I've tried a number of variations of the code below but not getting the desired results. It's something in the nested while loop that's throwing it out. This code is in draft stage I have to make it more memory efficient etc and tidy it up. I'm just interested in

问题 I'm currently making a math game where the user has 60 seconds to answer as many questions as possible. As of now, I have everything working except for the timer which should either count down to 0 or count up to 60 then stop the game. Right now, I have the timer set to time.clock() to count up to 60 and while the timer is less than that, the game will continue to run. For some reason however, the time.clock() isn't working as I expect it to. I also tried running two while loops at the same