isnullorempty

I am using gnuplot 4.6 . Also, I know that a similar question was asked more than a year ago here . The answer to that requires to write a small bash script. I want to know if it is possible to achieve this from within gnuplot script, especially when gnuplot-4.6 has so many cool features added. I am trying to achieve something like this : set xrange[xL:xU] set yrange[yL:yU] plot "file1.dat" using 1:2 w l lt 1 lw 1 lc 3,\ "file2.dat" using 1:2 w l lt 1 lw 1 lc 3 I am repeating the above process in a loop and the xrange & yrange parameters are being updated in each iteration. Also, I am saving

In PHP, I want to check if a variable has not been set/defined, where setting a variable NULL is considered set/defined . I'm aware everything here: http://php.net/manual/en/types.comparisons.php including isset(), empty(), and is_null(). None of these appear to be what I'm looking for. Consider the following example: <?php $myNull = null; echo 'isset($myNull): "'.isset($myNull).'"<br />'; echo '$myNull value = "'.$myNull . '"<br />'; echo "<br />"; echo 'isset($myUndefined): "'.isset($myUndefined).'"<br />'; echo '$myUndefined value = "'.$myUndefined . '"<br />'; ?> This example outputs

In SQLite, how can I select records where some_column is empty? Empty counts as both NULL and "". There are several ways, like: where some_column is null or some_column = '' or where ifnull(some_column, '') = '' or where coalesce(some_column, '') = '' of where ifnull(length(some_column), 0) = 0 It looks like you can simply do: SELECT * FROM your_table WHERE some_column IS NULL OR some_column = ''; Test case: CREATE TABLE your_table (id int, some_column varchar(10)); INSERT INTO your_table VALUES (1, NULL); INSERT INTO your_table VALUES (2, ''); INSERT INTO your_table VALUES (3, 'test'); INSERT

I know generally empty List is more prefer than NULL. But I am going to return NULL, for mainly two reasons I have to check and handle null values explicitly, avoiding bugs and attacks. It is easy to perform ?? operation afterwards to get a return value. For strings, we have IsNullOrEmpty. Is there anything from C# itself doing the same thing for List or IEnumerable? Matthew Vines nothing baked into the framework, but it's a pretty straight forward extension method. See here /// <summary> /// Determines whether the collection is null or contains no elements. /// </summary> /// <typeparam name=

I have a list of objects populated from a database. I need to display an error message if the list is empty and display a grid view otherwise. How do I check if a List<T> is empty in C#? Tim Schmelter Why not... bool isEmpty = !list.Any(); if(isEmpty) { // error message } else { // show grid } The GridView has also an EmptyDataTemplate which is shown if the datasource is empty. This is an approach in ASP.NET: <emptydatarowstyle backcolor="LightBlue" forecolor="Red"/> <emptydatatemplate> <asp:image id="NoDataErrorImg" imageurl="~/images/NoDataError.jpg" runat="server"/> No Data Found! <

I have a data frame where all the variables are of character type. Many of the columns are completely empty, i.e. only the variable headers are there, but no values. Is there any way to subset out the empty columns? If your empty columns are really empty character columns, something like the following should work. It will need to be modified if your "empty" character columns include, say, spaces. Sample data: mydf <- data.frame( A = c("a", "b"), B = c("y", ""), C = c("", ""), D = c("", ""), E = c("", "z") ) mydf # A B C D E # 1 a y # 2 b z Identifying and removing the "empty" columns. mydf[

I usually use something like this for various reasons throughout an application: if (String.IsNullOrEmpty(strFoo)) { FooTextBox.Text = "0"; } else { FooTextBox.Text = strFoo; } If I'm going to be using it a lot I will create a method that returns the desired string. For example: public string NonBlankValueOf(string strTestString) { if (String.IsNullOrEmpty(strTestString)) return "0"; else return strTestString; } and use it like: FooTextBox.Text = NonBlankValueOf(strFoo); I always wondered if there was something that was part of C# that would do this for me. Something that could be called like: