conditional-statements

问题 Whenever I try to run the program, an error pops up saying "string literal in condition (on line 10)". What am I doing wrong? puts "Welcome to the best calculator there is. Would you like to (a) calculate the area of a geometric shape or (b) calculate the equation of a parabola? Please enter an 'a' or a 'b' to get started." response = gets.chomp if response == "a" or "A" puts "ok." elsif response == "b" or "B" puts "awesome." else puts "I'm sorry. I did not get that. Please try again." end

问题 Let's say I have a TABLE a in which a COLUMN data is the one to join on for 2 other tables ( TABLE b and TABLE c ) because I want to get a COLUMN info in b or c . The thing is a.data will match only with b.data or only with c.data . How can I get b.info or c.info based on a ? How far did I try: After many attempts with obviously wrong syntax, the best I did was in 2 queries: SELECT b.info FROM a INNER JOIN b ON a.data = b.data SELECT c.info FROM a INNER JOIN c ON a.data = c.data I would like

问题 If you have code like this: if (A > X && B > Y) { Action1(); } else if(A > X || B > Y) { Action2(); } With A > X and B > Y , will both parts of the if-else-if ladder be executed? I'm dealing with Java code where this is present. I normally work in C++, but am an extremely new (and sporadic) programmer in both languages. 回答1: No, they won't both execute. It goes in order of how you've written them, and logically this makes sense; Even though the second one reads 'else if', you can still think

问题 I am reading about Condition in java.util.concurrent.locks.Condition . Condition factors out the Object monitor methods (wait, notify and notifyAll) >into distinct objects to give the effect of having multiple wait-sets per object, by combining them with the use of arbitrary Lock implementations. Can somebody explain me this? How this is a benefit over normal synchronization blocks or method? 回答1: One Lock can be associated with many Conditions. Lock is an "object", each condition is a

问题 I have script like this $number = range(0, 9); when I have condition like this if (in_array('@', $number) === true) { echo "true"; }else "false"; and output: true and my question is why the symbols is the same whit any number in array $number?? I want symbols just symbols not number. example I want like this if (in_array('@', $number) === true) { echo "true"; }else "false"; output : false 回答1: From the documentation for in_array(): If the third parameter strict is set to TRUE then the in

问题 I have code in my C++ application that generally does this: bool myFlag = false; while (/*some finite condition unrelated to myFlag*/) { if (...) { // statements, unrelated to myFlag } else { // set myFlag to true, perhaps only if it was false before? } } if (myFlag) { // Do something... } The question I have pertains to the else statement of my code. Basically, my loop may set the value of myFlag from false to true, based on a certain condition not being met. Never will the flag be unset

问题 I am trying to color points of an pandas dataframe dependend on TWO conditions. Example: If value of col1 > a (float) AND value of col2- value of col3 < b (float), then value of col 4 = string, else: other string. I have tried so many different ways now and everything I found online was only depending on one condition. My example code always raises the Error: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all(). Here's the code. Tried several

问题 I want to make a new list from another list of words; when a certain condition of the word is met. In this case I want to add all words that have the length of 9 to a new list. I have used : resultReal = [y for y in resultVital if not len(y) < 4] to remove all entries that are under the length of 4. However, I do not want to remove the entries now. I want to create a new list with the words, but keeping them in the old list. Perhaps something like this: if len(word) == 9: newlist.append()

问题 I have a database with companies and their products, I want for each company to have a separate product id sequence. I know that postgresql can't do this, the only way is to have a separate sequence for each company but this is cumbersome. I thought about a solution to have a separate table to hold the sequences CREATE TABLE "sequence" ( "table" character varying(25), company_id integer DEFAULT 0, "value" integer ) "table" will be holt the table name for the sequence, such as products,

问题 I'm writing some code which will check to see if a file is available to be checked out of SharePoint and, if it isn't, alert the user and tell them that the file is in use by someone else and who has it is in use by. I came across a piece of code at this site: http://www.xcelfiles.com/IsFileOpen.html#anchor_37 The code itself is pretty good and seems to work in test scenarios so I am planning to adapt it for my purposes but I'm having trouble understanding some of the syntax being used