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ModelState.IsValid == false, why?
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About "can it be that 0 errors and IsValid == false": here's MVC source code from https://github.com/Microsoft/referencesource/blob/master/System.Web/ModelBinding/ModelStateDictionary.cs#L37-L41
public bool IsValid {
get {
return Values.All(mo...
Regex expressions in Java, \\s vs. \\s+
...or many whitespaces. They're the so-called regular expression quantifiers, and they perform matches like this (taken from the documentation):
Greedy quantifiers
X? X, once or not at all
X* X, zero or more times
X+ X, one or more times
X{n} X, exactly n times
X{n,} X, at least n times
X{n,m}...
Unpacking, extended unpacking and nested extended unpacking
...lain with a few examples. Since you're talking about evaluating these "by hand," I'll suggest some simple substitution rules. Basically, you might find it easier to understand an expression if all the iterables are formatted in the same way.
For the purposes of unpacking only, the following substit...
What is a sealed trait?
...only extended in a single file, the compiler knows every possible subtypes and can reason about it.
For instance with the declaration:
sealed trait Answer
case object Yes extends Answer
case object No extends Answer
The compiler will emit a warning if a match is not exhaustive:
scala> val x:...
JavaScript by reference vs. by value [duplicate]
...omprehensive reading material on when JavaScript passes something by value and when by reference and when modifying a passed item affects the value outside a function and when not. I'm also interested in when assigning to another variable is by reference vs. by value and whether that follows any di...
I want to get the type of a variable at runtime
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So, strictly speaking, the "type of a variable" is always present, and can be passed around as a type parameter. For example:
val x = 5
def f[T](v: T) = v
f(x) // T is Int, the type of x
But depending on what you want to do, that won't help you. For instance, may want not to know what is ...
How to sort strings in JavaScript
...oid exceptions. localeCompare has been supported since Internet Explorer 6 and Firefox 1. You may also see the following code used that doesn't respect a locale:
if (item1.attr < item2.attr)
return -1;
if ( item1.attr > item2.attr)
return 1;
return 0;
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Getting and removing the first character of a string
...aracter. I was planning to 'pop' the first character of a string, use it, and repeat for the rest of the string.
6 Answers...
How do browser cookie domains work?
...n/subdomain cookie issues that I'm getting, I'd like to know how browsers handle cookies. If they do it in different ways, it would also be nice to know the differences.
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How to group dataframe rows into list in pandas groupby?
I have a pandas data frame df like:
12 Answers
12
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