There’s the null-safe dereferencing operator (?.) in Groovy… I think that’s what you’re after. (It’s also called the safe navigation operator.) For example: homePostcode = person?.homeAddress?.postcode This will give null if person, person.homeAddress or person.homeAddress.postcode is null. (This is now available in C# 6.0 but not in earlier versions)
What about string y = (Session[“key”] ?? “none”).ToString();
There is a new operator in php 5.3 which does this: ?: // A echo ‘A’ ?: ‘B’; // B echo ” ?: ‘B’; // B echo false ?: ‘B’; // B echo null ?: ‘B’; Source: http://www.php.net/ChangeLog-5.php#5.3.0
Powershell 7+ Powershell 7 introduces native null coalescing, null conditional assignment, and ternary operators in Powershell. Null Coalescing $null ?? 100 # Result is 100 “Evaluated” ?? (Expensive-Operation “Not Evaluated”) # Right side here is not evaluated Null Conditional Assignment $x = $null $x ??= 100 # $x is now 100 $x ??= 200 # … Read more
The example you were quoting from uses LINQ to Objects, where the implicit lambda expressions in the query are converted into delegates… whereas you’re using EF or similar, with IQueryable<T> queryies, where the lambda expressions are converted into expression trees. Expression trees don’t support the null conditional operator (or tuples). Just do it the old … Read more
Well, first of all, it’s much easier to chain than the standard ternary operator: string anybody = parm1 ?? localDefault ?? globalDefault; vs. string anyboby = (parm1 != null) ? parm1 : ((localDefault != null) ? localDefault : globalDefault); It also works well if a null-possible object isn’t a variable: string anybody = Parameters[“Name”] ?? … Read more
Use the If() operator with two arguments (Microsoft documentation): ‘ Variable first is a nullable type. Dim first? As Integer = 3 Dim second As Integer = 6 ‘ Variable first <> Nothing, so its value, 3, is returned. Console.WriteLine(If(first, second)) second = Nothing ‘ Variable first <> Nothing, so the value of first is … Read more
C# already lets us substitute values for null with ??. So all we need is an extension that converts an empty string to null, and then we use it like this: s.SiteNumber.NullIfEmpty() ?? “No Number”; Extension class: public static class StringExtensions { public static string NullIfEmpty(this string s) { return string.IsNullOrEmpty(s) ? null : s; … Read more
Sadly – no. The closest you can do is: int y = (x != null) ? x : -1; Of course, you can wrap this up in library methods if you feel the need to (it’s unlikely to cut down on length much), but at the syntax level there isn’t anything more succinct available.
other = s or “some default value” Ok, it must be clarified how the or operator works. It is a boolean operator, so it works in a boolean context. If the values are not boolean, they are converted to boolean for the purposes of the operator. Note that the or operator does not return only … Read more