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How can I add a key/value pair to a JavaScript object?
...re.
_.merge (Lodash only)
The second object will overwrite or add to the base object.
undefined values are not copied.
var obj = {key1: "value1", key2: "value2"};
var obj2 = {key2:"value4", key3: "value3", key4: undefined};
_.merge(obj, obj2);
console.log(obj);
// → {key1: "value1", key2: "valu...
Why do indexes in XPath start with 1 and not 0?
...ng about our experience with VBScript with its odd features such as 1-based index instead of 0-based indexes like almost every other language has, the reasoning being that it was a language for users (e.g. Excel VBA) instead of a language for developers.
...
Many-to-many relationship with the same model in rails?
...n-standard things. It will look as follows:
class Post < ActiveRecord::Base
has_and_belongs_to_many(:posts,
:join_table => "post_connections",
:foreign_key => "post_a_id",
:association_foreign_key => "post_b_id")
end
And that should simply work! Here's an example irb ses...
How to search a specific value in all tables (PostgreSQL)?
...
How about dumping the contents of the database, then using grep?
$ pg_dump --data-only --inserts -U postgres your-db-name > a.tmp
$ grep United a.tmp
INSERT INTO countries VALUES ('US', 'United States');
INSERT INTO countries VALUES ('GB', 'United Kingdom');
Th...
Implements vs extends: When to use? What's the difference?
...ments used for implementing an interface and extends used for extension of base class behaviour or abstract class.
extends: A derived class can extend a base class. You may redefine the behaviour of an established relation. Derived class "is a" base class type
implements: You are implementing a c...
Executing multiple commands from a Windows cmd script
...
@TheM Windows distinguishes between GUI-based and command-based applications (there is a flag in near the beginning of the EXE file). If you start a GUI-based application from the command line it always appears to end immediately since it is completely detached fro...
PHP $_SERVER['HTTP_HOST'] vs. $_SERVER['SERVER_NAME'], am I understanding the man pages correctly?
...$_SERVER['HTTP_HOST'] (aside from implementing some other custom handshake based on the user request). Pro devs do not trust the things they don't understand completely. So they either have their SAPI setup perfectly correctly (in which case the option they use will give the correct result), or they...
SQL Client for Mac OS X that works with MS SQL Server [closed]
...
Native Apps
SQLPro for MSSQL
Navicat
Valentina Studio
TablePlus
Java-Based
Oracle SQL Developer (free)
SQuirrel SQL (free, open source)
Razor SQL
DB Visualizer
DBeaver (free, open source)
SQL Workbench/J (free, open source)
JetBrains DataGrip
Metabase (free, open source)
Netbeans (free, open...
How to get request URI without context path?
... return null), then your best bet is to substring the request URI yourself based on the context path's length using the usual String method:
HttpServletRequest request = (HttpServletRequest) req;
String path = request.getRequestURI().substring(request.getContextPath().length());
// ...
...
How to import multiple .csv files at once?
...
A speedy and succinct tidyverse solution:
(more than twice as fast as Base R's read.csv)
tbl <-
list.files(pattern = "*.csv") %>%
map_df(~read_csv(.))
and data.table's fread() can even cut those load times by half again. (for 1/4 the Base R times)
library(data.table)
tbl_fre...