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How to check if a variable exists in a FreeMarker template?
... This only check if the var exists. But if you have an empty String in "userName", the <#if userName??> will return true !! See @user1546081 answer on this page to address this issue.
– Adrien Be
Jan 15 '13 at 10:22
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Will ConfigurationManager.AppSettings[“blah”] throw an exception if “blah” doesn't exist?
...
From the MSDN documentation for NameValueCollection.Item Property (String):
Caution
This property returns null in the following cases: 1) if the specified key is not found; and 2) if the specified key is found and its associated value is null. This property does not distinguish between the ...
What actually causes a Stack Overflow error? [duplicate]
...lass Test
{
final static int CALLS = 710;
public static void main(String[] args)
{
final Functor[] functors = new Functor[CALLS];
for (int i = 0; i < CALLS; i++)
{
final int finalInt = i;
functors[i] = new Functor()
{
...
Regular expression for a hexadecimal number?
...an also recognize hex patterns like: '535GH0G73' For Java, we can use e.g String.matches() for checking this.. Thank you guys for the response :)
– saurcery
Feb 10 '12 at 2:23
2
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Count cells that contain any text
...nts. Text entries and numbers are counted, even when they contain an empty string of length 0.
Example:
Function in A7
=COUNTA(A1:A6)
Range:
A1 a
A2 b
A3 banana
A4 42
A5
A6
A7 4 -> result
Google spreadsheet function list contains a list of all available functions for future reference h...
Error handling in C code
...r if struct is really large) and have a function to format the struct as a string.
– Winger Sendon
Sep 27 '18 at 22:50
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Moving from CVS to Git: $Id$ equivalent?
...44934b1cd774e6d4 $
Some good information is in How do I enable the ident string for a Git repository?.
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Warning message: In `…` : invalid factor level, NA generated
...e" variable was made a factor and "lunch" was not a defined level. Use the stringsAsFactors = FALSE flag when making your data frame to force "Type" to be a character.
> fixed <- data.frame("Type" = character(3), "Amount" = numeric(3))
> str(fixed)
'data.frame': 3 obs. of 2 variables:
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How to find all the subclasses of a class given its name?
...me". Since Python classes are first-class objects, you don't need to use a string with the class's name in place of the class or anything like that. You can just use the class directly, and you probably should.
If you do have a string representing the name of a class and you want to find that class...
How do I specify different Layouts in the ASP.NET MVC 3 razor ViewStart file?
...ass LayoutInjecterAttribute : ActionFilterAttribute
{
private readonly string _masterName;
public LayoutInjecterAttribute(string masterName)
{
_masterName = masterName;
}
public override void OnActionExecuted(ActionExecutedContext filterContext)
{
base.OnActi...