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Concatenate two string literals
..., for the null terminator). When you use an array in most contexts, it is converted into a pointer to its initial element.
So, when you try to do "Hello" + ",world", what you're really trying to do is add two const char*s together, which isn't possible (what would it mean to add two pointers tog...
Custom sort function in ng-repeat
...dless of sort order.
To workaround this, we can create a custom filter to convert the object to an array, and then apply a custom sort function before returning the collection.
myApp.filter('orderByValue', function () {
// custom value function for sorting
function myValueFunction(card) {
...
How to implement a many-to-many relationship in PostgreSQL?
... product (
product_id serial PRIMARY KEY -- implicit primary key constraint
, product text NOT NULL
, price numeric NOT NULL DEFAULT 0
);
CREATE TABLE bill (
bill_id serial PRIMARY KEY
, bill text NOT NULL
, billdate date NOT NULL DEFAULT CURRENT_DATE
);
CREATE TABLE bill_product...
How can I list ALL DNS records?
...ost is a simple utility for performing DNS lookups. It is normally used to convert names to IP addresses and vice versa. When no arguments or options are given, host prints a short summary of its command line arguments and options.
...
Cannot change column used in a foreign key constraint
...food
DROP FOREIGN KEY fk_fav_food_person_id,
MODIFY person_id SMALLINT UNSIGNED;
Now you can change you person_id
ALTER TABLE person MODIFY person_id SMALLINT UNSIGNED AUTO_INCREMENT;
recreate foreign key
ALTER TABLE favorite_food
ADD CONSTRAINT fk_fav_food_person_id FOREIGN KEY (...
How do I check the difference, in seconds, between two dates?
... = "%H:%M:%S"
# You could also pass datetime.time object in this part and convert it to string.
time_start = str('09:00:00')
time_end = str('18:00:00')
# Then get the difference here.
diff = datetime.strptime(time_end, date_format) - datetime.strptime(time_start, date_format)
# Get the time ...
Entity Framework is Too Slow. What are my options? [closed]
...y not use both? EF handles stored procedures and raw SQL just fine. I just converted a LINQ-to-SQL query that took 10+ seconds into a SP that takes ~1 second, but I'm not gonna throw all LINQ-to-SQL out. It saved a LOT of time in other simpler cases, with less code and less room for error and the qu...
Throwing the fattest people off of an overloaded airplane.
...d a MinHeap class. (Yes, my example is in C#. I think you get the idea.)
int targetTotal = 3000;
int totalWeight = 0;
// this creates an empty heap!
var myHeap = new MinHeap<Passenger>(/* need comparer here to order by weight */);
foreach (var pass in passengers)
{
if (totalWeight < t...
Best Practice: Access form elements by HTML id or name attribute?
... normal JS object, and elements.foo or elements["foo"] is actually getting converted to elements.namedItem("foo"). i.e. you're calling a DOM-defined function, not referencing a JS property!
– Doin
Jul 21 '19 at 16:36
...
techniques for obscuring sensitive strings in C++
... binary, you could for instance make sure that the key is not within the printable range.
Obscuring key with XOR
For instance, you could use XOR to split the key into two byte arrays:
key = key1 XOR key2
If you create key1 with the same byte-length as key you can use (completely) random byte va...