if-statement

问题 To begin, the code that I have got up to this point is below. The calculator does everything I want it to, minus the fact that it still includes negative numbers in its calculations. I would like for it to do nothing if the number presented as the radius is less than zero, yet still calculate if the number is non-negative. However, I am having issues with using an if statement. I have not used these before, as I am really just a beginner. I just need a push in the right direction. Do I need

问题 Suppose we have some variables x and y, and the following if statement which involves bit shifting: if (x<<y) I've read some posts which also deal with the issue of using bit shifting with variables (of some type) and inside if statement, but unfortunately I haven't been able to reach a unequivocal conclusion whether it is an error or not. I assume that if it is an error, then it's a semantic error or a run-time error . But is it necessarily en error ? 回答1: If x is of an unsigned integer type

问题 This question already has answers here : Compare two objects with .equals() and == operator (16 answers) Closed 5 years ago . I am trying to create a type of triangle app for my homework but when I tried to use if statement in java, for some reason, when I click on the "Generate Button", it keeps on showing the " Scalene Triangle: No Congruent Sides" , even thought my inputs are : 2,2,3 which should be an Isosceles Triangle. Please help. Is my logic wrong or something? Thanks a lot. Java code

问题 I need to create a "flag" column within my main data frame that flags rows where the date is within a specific time range. That time range comes from a second data frame. I think I'm just stuck on the ifelse (or if) statement because there are NA's in the flag column. Maybe ifelse isn't the way to go. Here's some sample data: # main data frame date <- seq(as.Date("2014-07-21"), as.Date("2014-09-11"), by = "day") group <- letters[1:4] datereps <- rep(date, length(group)) groupreps <- rep(group

问题 I am trying to do the following with wordpress : "If is NOT page 92, OR page parent is NOT 92." Here is what I have: <?php if (!is_page(92) || $post->post_parent !== 92) { echo $foo; } ?> If I use one or the other as condition, it works; When I add the second condition, it breaks. Any help would be well appreciated. Cheers! 回答1: Your problem is probably in using || instead of &&. You want it to echo if you are not on page 92 AND you are not in a subpage of page 92. Let's say you're on page 92

问题 If the nested if-statement doesn't fulfill a condition, how do I continue on to the outer if? Eg. I have this (very impractical) example: a = 2 if( a > 1 ): if( a == 3 ): print "yes" elif( a == 2 ): print "yes" I want a == 2 to be checked next. How would I do this? (I have multiple conditions in that nested if that I need to check so I'd rather not have a huge string of and/or statements in that one outer-if. I also have more than one elif statement so I don't want to mash all the elifs

问题 If the nested if-statement doesn't fulfill a condition, how do I continue on to the outer if? Eg. I have this (very impractical) example: a = 2 if( a > 1 ): if( a == 3 ): print "yes" elif( a == 2 ): print "yes" I want a == 2 to be checked next. How would I do this? (I have multiple conditions in that nested if that I need to check so I'd rather not have a huge string of and/or statements in that one outer-if. I also have more than one elif statement so I don't want to mash all the elifs

问题 Usually, I use square brackets in the if statement: if [ "$name" = 'Bob' ]; then ... But, when I check if grep succeeded I don't use the square brackets: if grep -q "$text" $file ; then ... When are the square brackets necessary in the if statement? 回答1: The square brackets are a synonym for the test command. An if statement checks the exit status of a command in order to decide which branch to take. grep -q "$text" is a command, but "$name" = 'Bob' is not--it's just an expression. test is a

问题 In ocaml, I want to have many nested if statements and a return value on each of the conditions. The code is becoming complicated like this. let func arg1 arg2 = if condition1 then arg1+arg2 else ( //code1 if condition2 then arg1*arg2 else ( //code2 if condition3 then arg1+arg2 else ( //code3 ) ) ) Instead of such nested statements can I have code like this? let func arg1 arg2 = if condition1 then arg1+arg2 //code1 if condition2 then arg1*arg2 //code2 if condition3 then arg1+arg2 //code3 回答1:

问题 In ocaml, I want to have many nested if statements and a return value on each of the conditions. The code is becoming complicated like this. let func arg1 arg2 = if condition1 then arg1+arg2 else ( //code1 if condition2 then arg1*arg2 else ( //code2 if condition3 then arg1+arg2 else ( //code3 ) ) ) Instead of such nested statements can I have code like this? let func arg1 arg2 = if condition1 then arg1+arg2 //code1 if condition2 then arg1*arg2 //code2 if condition3 then arg1+arg2 //code3 回答1: