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Java: how do I get a class literal from a generic type?
...pe erasure.
Java generics are little more than syntactic sugar for Object casts. To demonstrate:
List<Integer> list1 = new ArrayList<Integer>();
List<String> list2 = (List<String>)list1;
list2.add("foo"); // perfectly legal
The only instance where generic type information...
Can you get the column names from a SqlDataReader?
...lumns = reader.GetSchemaTable().Rows
.Cast<DataRow>()
.Select(r => (string)r["ColumnName"])
.ToList();
//Or
var columns = Enumerable.Range(0, reader.FieldCount)
...
Java: Instanceof and Generics
...(Object o) {
try {
abstractMethod((T) o);
} catch (ClassCastException e) {
//...
You are casting the object to T (your generic type), just to fool the compiler. Your cast does nothing at runtime, but you will still get a ClassCastException when you try to pass the wrong type of...
What is the !! (not not) operator in JavaScript?
...
An easy way to describe it is: Boolean(5) === !!5; Same casting, fewer characters.
– Micah Snyder
Apr 24 '09 at 18:27
43
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How do I convert a string to enum in TypeScript?
...
So we can use typecast: let s = "Green"; let typedColor = <keyof typeof Color> s;
– SergeyT
Jun 8 '17 at 13:06
...
Why does integer division in C# return an integer and not a float?
... it, and that every time you do division you'll always need to remember to cast to floating points, you are mistaken.
First off, integer division is quite a bit faster, so if you only need a whole number result, one would want to use the more efficient algorithm.
Secondly, there are a number of al...
How do you list the primary key of a SQL Server table?
...rimary Key and Foreign Keys ) and at the end of query put table name
/* CAST IS DONE , SO THAT OUTPUT INTEXT FILE REMAINS WITH SCREEN LIMIT*/
WITH ALL_KEYS_IN_TABLE (CONSTRAINT_NAME,CONSTRAINT_TYPE,PARENT_TABLE_NAME,PARENT_COL_NAME,PARENT_COL_NAME_DATA_TYPE,REFERENCE_TABLE_NAME,REFERENCE_COL_NA...
Signed to unsigned conversion in C - is it always safe?
...
As was previously answered, you can cast back and forth between signed and unsigned without a problem. The border case for signed integers is -1 (0xFFFFFFFF). Try adding and subtracting from that and you'll find that you can cast back and have it be correct.
...
Get all column names of a DataTable into string array using (LINQ/Predicate)
...
Try this (LINQ method syntax):
string[] columnNames = dt.Columns.Cast<DataColumn>()
.Select(x => x.ColumnName)
.ToArray();
or in LINQ Query syntax:
string[] columnNames = (from dc in dt.Columns.Cast<DataCo...
how to convert array values from string to int?
...
intval() is less performant than (int) cast. So better use another solution with (int). see Method 3 here
– Fabian Picone
Apr 19 '16 at 7:24
...