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What is the yield keyword used for in C#?
...e function returns an object that implements the IEnumerable<object> interface. If a calling function starts foreaching over this object, the function is called again until it "yields". This is syntactic sugar introduced in C# 2.0. In earlier versions you had to create your own IEnumerable and...
Creating an index on a table variable
... that first.
SQL Server 2014
In addition to the methods of adding constraint based indexes discussed below SQL Server 2014 also allows non unique indexes to be specified directly with inline syntax on table variable declarations.
Example syntax for that is below.
/*SQL Server 2014+ compatible i...
Get the length of a String
...0;, Snail &#128012;, Penguin &#128039;, Dromedary &#128042;"
println("unusualMenagerie has \(count(unusualMenagerie)) characters")
// prints "unusualMenagerie has 40 characters"
right from the Apple Swift Guide
(note, for versions of Swift earlier than 1.2, this would be countElements...
How to overload the operator++ in two different ways for postfix a++ and prefix ++a?
...plement postfix in terms of prefix.
//
Number operator++ (int) // postfix ++
{
Number result(*this); // make a copy for result
++(*this); // Now use the prefix version to do the work
return result; // return the copy ...
Linq list of lists to single list
...
Here is a sample code for you:
List<int> listA = new List<int> { 1, 2, 3, 4, 5, 6 };
List<int> listB = new List<int> { 11, 12, 13, 14, 15, 16 };
List<List<int>> listOfLists = new List<List<int>> { listA, listB };
...
What is the use of static variable in C#? When to use it? Why can't I declare the static variable in
...
Example without declaring it static:
public class Variable
{
public int i = 5;
public void test()
{
i = i + 5;
Console.WriteLine(i);
}
}
public class Exercise
{
static void Main()
{
Variable var = new Variable();
var.test();
Variab...
Base64 encoding and decoding in client-side Javascript
...JavaScript');
// If we don't use toString(), JavaScript assumes we want to convert the object to utf8.
// We can make it convert to other formats by passing the encoding type to toString().
var s = b.toString('base64');
And here is how you decode base64 encoded strings:
var b = new Buffer('SmF2YVNj...
How to elegantly check if a number is within a range?
...
There are a lot of options:
int x = 30;
if (Enumerable.Range(1,100).Contains(x))
//true
if (x >= 1 && x <= 100)
//true
Also, check out this SO post for regex options.
...
Java String - See if a string contains only numbers and not letters
...ontains only numerics.
If you actually want to use the numeric value, use Integer.parseInt() or Double.parseDouble() as others have explained below.
As a side note, it's generally considered bad practice to compare boolean values to true or false. Just use if (condition) or if (!condition).
...
What is the C++ function to raise a number to a power?
...e <cmath> header has these overloads:
pow(float, float);
pow(float, int);
pow(double, double); // taken over from C
pow(double, int);
pow(long double, long double);
pow(long double, int);
Now you can't just do
pow(2, N)
with N being an int, because it doesn't know which of float, double...