expression

问题 Can you do an if-then-else statement inside a JSP expression? EDIT : Specifically I was looking for a JSP solution, not a JSTL solution. But some JSTL solutions below are highly rated and are very welcome. Just please do not vote me down for a duplicate question because one has already been asked about JSTL. 回答1: In JSP EL 2.0, you can do that using the ternary operator. For instance: <option value="1" ${param.number == 1 ? 'selected' : ''}>First option</option> What it does is it checks JSP

问题 I build graphics in which I use regular and bold font for titles and/or labels. They contain symbols, text and numbers which I combine using ?plotmath . I noticed that using bold within the expression changes only character strings to bold face, but not numbers which are part of the expression. See this minimal example: x <- y <- 1:10 plot(x, y, xlab=bquote(bold(foo[bar]^2==.(mean(x))))) In this example, there is a numeric superscript on the LHS, and an evaluated expression on the RHS of the

问题 I'm somehow new to Java so my question can seem trivial, however i cannot find an answer to it anywhere in my books. I want to initiatie a dialog with a user in which he would enter an arithmetic expression (ex. (2*x+y)) And then print out the result for such expression (for given values of x and y) String EXPRESION = null; EXPRESION = JOptionPane.showInputDialog("Please enter expresion for dy/dx"); double x = 1.4; double y = 5; double output = HERE IS THE PROBLEM JOptionPane

问题 I've noticed many languages like Ruby and CofeeScript (well a transcompiler) support everything being an expression. Now it makes the language somewhat simple to understand and definitely seems neat at the surface, but I was looking maybe for some scholarly publications about the positives and negatives of the two approaches. It would be beneficial if the publications had clear examples that compared the benefits of having everything be an expression vs., well, not. Examples in CoffeeScript

问题 I have an Execute SQL Task using this expression: @[User::SQLExportError] + (DT_WSTR,30)@[User::Id] The expression evaluates correctly to: select count(*) as ErrorTableCount from [myschema].Error where SPName in ('export/INSERT','export/DELETE') and Id = 1000 In this same sql task I want to capture the as ErrorTableCount into a single row result set with the ResultName called: ErrorTableCount Variable Name called: User::ErrorTableCount I am getting the red circle/x cross telling me: There

问题 I have an Execute SQL Task using this expression: @[User::SQLExportError] + (DT_WSTR,30)@[User::Id] The expression evaluates correctly to: select count(*) as ErrorTableCount from [myschema].Error where SPName in ('export/INSERT','export/DELETE') and Id = 1000 In this same sql task I want to capture the as ErrorTableCount into a single row result set with the ResultName called: ErrorTableCount Variable Name called: User::ErrorTableCount I am getting the red circle/x cross telling me: There

问题 I came across this code and wanted others to provide their point of view... is it good or bad ? ;) Class ReportClass { public string ReportName {get; set;} } Then it was used as follows in code: displayReport(ReportClass.ReportName = cmbReportName.SelectedValue.ToString()) That is about the simplest form example I can give you. Quetion is... why can't I find examples ? What would this be called? Is this just asking for trouble? EDIT: I'm referring to the inplace assignment. Which I wasn't

问题 I'm using Dynamic Expression API ( System.Linq.Dynamic ) with LINQ to Entities. My LINQ query is below. var query = this.db.Products.AsQueryable() .Where(strCondition) .OrderBy("ProductNumber") .Select("new(ProductNumber, ProductDescription, ProductCategory.Name)"); Now that I have the "query", I don't know how to get the value of each of the field. string strTemp; foreach (var item in query) { strTemp = item.? } It's anonymous type so I can't really use strongly type to get the value. What

问题 I need to add a line break but I am struggling with the atop function in expression() . The main is the part I would like to break into two lines. > plot (DAC~Chlo,data=brazilw, pch=15,col="red",cex=0.5, main=expression("Fig. 3. Relationship between diffuse attenuation coefficient at 490 nm (K"[d]*") and chlorophyll concentration at three coral reef sites"), xlab=expression("Chlorophyll concentration (mg "*m^{-3}*")"), cex.lab=0.8, cex.main=0.8, cex.axis=0.8, font.main=1, ylim=c(0,0.3), xlim

问题 I am currently trying to write some code which turns C# Expressions into text. To do this, I need to not only walk through the Expression tree, but also evaluate just a little part of it - in order to get the current value of a local variable. I am finding very hard to put into words, so here is the pseudo-code instead. The missing part is in the first method: public class Program { private static void DumpExpression(Expression expression) { // how do I dump out here some text like: // set T2