if-statement

问题 I'm trying to count all values different than some specific criteria on the same row in a Google sheet that is feed via a google form but the final count shows "1". The row I'm counting from corresponds to a multiple choice question that has an 'other' option so the user can enter other values and I'm trying to count the number of 'other' values in the row. I tried normal count and couldif but when you use a <> it ends up counting to infinite if you want to check a B2:B range (B1 Is the

问题 I'm having an issue with scope in an if statement, at least, I'm pretty sure that is where my error is, and I'm not sure of how to fix the issue (I'm pretty new at programming). Basically, it seems that if I declare something within an if statement, the variable (in this case, an array of structs) does not exist outside of the if statement. However, I really need the declaration for the array to be inside of an if/else because the size of the array is dependent upon N, so how can I fix this

问题 I'd like to know if there is any efficiency difference between using if statement or switch. For example: if(){ //code } else if(){ //code } else{ //code } I believe that program needs to go and check all of the if statement even if the first if statement was true. switch(i){ case 1: //code break; case 2: //code break; But in the switch, there is a break command. Is my approaching right? If not, could you explain the efficiency difference between them? 回答1: Switch perf is better than if else

问题 I've had no real luck getting a concise answer for this comparison by using Google and rather than do my own time consuming evaluations, I thought I would ask first. I'm fairly sure that a switch statement using Enums would perform faster than an if-then-else statement, though whether or not it is a noticable difference is another question. Could someone shed some light on this for me? Thanks for the quick responses guys, I will keep this in mind for future projects. 回答1: Yeap, it does,

问题 This question already has answers here : Boolean operators && and || (3 answers) Closed 2 years ago . I have read many of the if statement posts but have not been able to find an answer to my simple problem. I would like to create a new column in the data frame 'tester' based on a multiple condition if statement. tester<- as.data.frame(matrix(data=c(seq(1,300,by=1.5)), ncol=4)) if (tester$V3> 200 && tester$V4>250){tester[,5] <- "one"} else tester$V5 <-NA This gives me NAs for the entire

问题 I need to use if statement inside where clause in sql. Select * from Customer WHERE (I.IsClose=@ISClose OR @ISClose is NULL) AND (C.FirstName like '%'+@ClientName+'%' or @ClientName is NULL ) AND if (@Value=2) begin (I.RecurringCharge=@Total or @Total is NULL ) end else if(@Value=3) begin (I.RecurringCharge like '%'+cast(@Total as varchar(50))+'%' or @Total is NULL ) end Note:This is not the complete code.Everything is defined in SP.I Just written the code that was needed to understand the

问题 Apologies if this has been asked before, but I couldn't see it anywhere. Essentially I've come across a scenario where i need to make use of an if statement inside a lambda function. What makes it difficult is that ideally it needs to be in a single line of code (if thats even possible?) Normally, i would write this: T = 250 if (T > 200): rate = 200*exp(-T) else: rate = 400*exp(-T) return (rate) However i need it to look like this: rate = lambda(T) : if (T>200): return(200*exp(-T)); else:

问题 I'm trying to write a script that will check two error flags, and in case one flag (or both) are changed it'll echo-- error happened. My script: my_error_flag=0 my_error_flag_o=0 do something..... if [[ "$my_error_flag"=="1" || "$my_error_flag_o"=="2" ] || [ "$my_error_flag"="1" && "$my_error_flag_o"="2" ]]; then echo "$my_error_flag" else echo "no flag" fi Basically, it should be, something along: if ((a=1 or b=2) or (a=1 and b=2)) then display error else no error fi The error I get is: line

问题 I have a class Animal , and its subclass Dog . I often find myself coding the following lines: if (animal is Dog) { Dog dog = animal as Dog; dog.Name; ... } For the variable Animal animal; . Is there some syntax that allows me to write something like: if (Dog dog = animal as Dog) { dog.Name; ... } 回答1: The answer below was written years ago and updated over time. As of C# 7, you can use pattern matching: if (animal is Dog dog) { // Use dog here } Note that dog is still in scope after the if

问题 Currently having trouble with breaking this for loop. I want to break it if the variable is not found in this list so it can move two another for loop. It expects an indented block for the top of the for loop, but if I change the position of the break or of the start of the for loop, it doesn't work. Help! while cyclenumb <= 10000: for x in userpassword[k]: for z in lowercaselist: if x in z: newpasswordlist.append(z) k +=1 break else: for x in userpassword[k]: for z in uppercaselist: if x in