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Performance difference for control structures 'for' and 'foreach' in C#
...uld all depend upon how the enumerator is implemented versus how the lists indexer is implemented. As it turns out the enumerator for types based on arrays are normally written something like this:
private static IEnumerable<T> MyEnum(List<T> list)
{
for (int i = 0; i < list.Coun...
How to iterate through SparseArray?
...a SparseArray (for Android) ? I used sparsearray to easily get values by index. I could not find one.
10 Answers
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Why does this iterative list-growing code give IndexError: list assignment index out of range?
...o realise is that a list object will not allow you to assign a value to an index that doesn't exist.
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Can I use git diff on untracked files?
...add -N the file (or --intent-to-add), which adds a zero-length blob to the index at that location. The upshot is that your "untracked" file now becomes a modification to add all the content to this zero-length file, and that shows up in the "git diff" output.
git diff
echo "this is a new file" >...
What is the difference between List (of T) and Collection(of T)?
...move items
List - allows items to have an order (accessing and removing by index)
Enumerable has no order. You cannot add or remove items from the set. You cannot even get a count of items in the set. It strictly lets you access each item in the set, one after the other.
Collection is a modifiabl...
Cannot resolve the collation conflict between “SQL_Latin1_General_CP1_CI_AS” and “Latin1_General_CI_
... here:
SELECT
fti.object_Id,
OBJECT_NAME(fti.object_id) 'Fulltext index',
fti.is_enabled,
i.name 'Index name',
OBJECT_NAME(i.object_id) 'Table name'
FROM
sys.fulltext_indexes fti
INNER JOIN
sys.indexes i ON fti.unique_index_id = i.index_id
You can then drop the fullt...
Rails has_and_belongs_to_many migration
... t.references :restaurant
t.references :user
end
add_index :restaurants_users, [:restaurant_id, :user_id]
add_index :restaurants_users, :user_id
end
def self.down
drop_table :restaurants_users
end
end
Rails 4
class CreateRestaurantsUsers < ActiveRecord::Mig...
Duplicating a MySQL table, indices, and data
...
To copy with indexes and triggers do these 2 queries:
CREATE TABLE newtable LIKE oldtable;
INSERT INTO newtable SELECT * FROM oldtable;
To copy just structure and data use this one:
CREATE TABLE tbl_new AS SELECT * FROM tbl_old;
I'...
What does the JSLint error 'body of a for in should be wrapped in an if statement' mean?
... 2
// filter_0
Do you see? It suddenly thinks filter_0 is another array index. Of course, it is not really a numeric index, but for in enumerates through object fields, not just numeric indexes. So we're now enumerating through every numeric index and filter_0. But filter_0 is not a field of any...
How do I discard unstaged changes in Git?
How do I discard changes in my working copy that are not in the index?
36 Answers
36
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