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Check if element exists in jQuery [duplicate]
How do I check if an element exists if the element is created by .append() method?
$('elemId').length doesn't work for me.
...
Passing properties by reference in C#
...ion.
1. Return Value
string GetString(string input, string output)
{
if (!string.IsNullOrEmpty(input))
{
return input;
}
return output;
}
void Main()
{
var person = new Person();
person.Name = GetString("test", person.Name);
Debug.Assert(person.Name == "test");...
When to add what indexes in a table in Rails
...unique)" to the automatically created "id" column?
No, same as above
If I add index to two foreign keys at once (add_index (:users, [:category_id, :state_id]), what happens? How is this different from adding the index for each key?
Then the index is a combined index of the two columns. That ...
How to efficiently compare two unordered lists (not sets) in Python?
...be considered equal, because they have exactly the same elements, only in different order.
10 Answers
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How to automatically select all text on focus in WPF TextBox?
If I call SelectAll from a GotFocus event handler, it doesn't work with the mouse - the selection disappears as soon as mouse is released.
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LISTAGG in Oracle to return distinct values
... the_column)
from (
select distinct the_column
from the_table
) t
If you need more columns, something like this might be what you are looking for:
select col1, listagg(col2, ',') within group (order by col2)
from (
select col1,
col2,
row_number() over (partition by col...
How should I cast in VB.NET?
...
Those are all slightly different, and generally have an acceptable usage.
var.ToString() is going to give you the string representation of an object, regardless of what type it is. Use this if var is not a string already.
CStr(var) is the VB stri...
Removing all empty elements from a hash / YAML?
...dd a compact method to Hash like this
class Hash
def compact
delete_if { |k, v| v.nil? }
end
end
or for a version that supports recursion
class Hash
def compact(opts={})
inject({}) do |new_hash, (k,v)|
if !v.nil?
new_hash[k] = opts[:recurse] && v.class == Hash...
Listing all permutations of a string/integer
...ents, concatenated with every permutation of the other elements.
Example:
If the set just has one element -->
return it.
perm(a) -> a
If the set has two characters: for
each element in it: return the
element, with the permutation of the
rest of the elements added, like so:
perm(ab) ->
...
#if Not Debug in c#?
...
You would need to use:
#if !DEBUG
// Your code here
#endif
Or, if your symbol is actually Debug
#if !Debug
// Your code here
#endif
From the documentation, you can effectively treat DEBUG as a boolean. So you can do complex tests like:
...