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JavaScript: Object Rename Key
... this should be accepted answer, worked great for my use case. I had to convert an API response that was prefixing Country Names with unnecessary string. Turned Object into array of keys and mapped through each key with substring method and returned a new object with new key and value indexed by ...
Django South - table already exists
...ing database and app you can use the south conversion command
./manage.py convert_to_south myapp
This has to be applied before you do any changes to what is already in the database.
The convert_to_south command only works entirely on the first machine you run it on. Once you’ve committed the ...
foreach with index [duplicate]
...ublic static void Each<T>(this IEnumerable<T> ie, Action<T, int> action)
{
var i = 0;
foreach (var e in ie) action(e, i++);
}
And use it like so:
var strings = new List<string>();
strings.Each((str, n) =>
{
// hooray
});
Or to allow for break-like behaviou...
What is the performance cost of having a virtual method in a C++ class?
... class will have a virtual table, and every instance will have a virtual pointer.
9 Answers
...
Data structure: insert, remove, contains, get random element, all at O(1)
I was given this problem in an interview. How would you have answered?
14 Answers
14
...
Java's final vs. C++'s const
...e, later in Java only e.g.:
public class Foo {
void bar() {
final int a;
a = 10;
}
}
is legal in Java, but not C++ whereas:
public class Foo {
void bar() {
final int a;
a = 10;
a = 11; // Not legal, even in Java: a has already been assigned a value.
}
}
I...
Difference between encoding and encryption
... want to store text on a hard drive, you're going to have to find a way to convert your characters to bits. Alternatively, if all you have is a flash light, you might want to encode your text using Morse. The result is always "readable", provided you know how it's stored.
Encryption means you want ...
How to get the user input in Java?
...ner;
//...
Scanner scan = new Scanner(System.in);
String s = scan.next();
int i = scan.nextInt();
BufferedReader and InputStreamReader classes
import java.io.BufferedReader;
import java.io.InputStreamReader;
//...
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String s ...
Use of def, val, and var in scala
... Person) you are changing the age member variable.
And the last line:
println(person.age)
Here you are again calling the person method, which returns a new instance of class Person (with age set to 12). It's the same as this:
println(person().age)
...
Select all elements with “data-” attribute without using jQuery
...`[data-foo="${i}"]`)
Note even if you don't write value in string it gets converted to string like if I write
<div data-foo=1></div>
and then inspect the element in Chrome developer tool the element will be shown as below
<div data-foo="1"></div>
You can also cross verify ...