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JavaScript hashmap equivalent
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Hash your objects yourself manually, and use the resulting strings as keys for a regular JavaScript dictionary. After all, you are in the best position to know what makes your objects unique. That's what I do.
Example:
var key = function(obj){
// Some un...
What is the purpose of flush() in Java streams?
...Java, flush() method is used in streams. But I don't understand what are all the purpose of using this method?
6 Answers
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How can you make a custom keyboard in Android?
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First of all you will need a keyboard.xml file which will be placed in the res/xml folder (if the folder does not exist, created it).
<?xml version="1.0" encoding="utf-8"?>
<Keyboard xmlns:android="http://schemas.android.com...
Foreign Key to non-primary key
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If you really want to create a foreign key to a non-primary key, it MUST be a column that has a unique constraint on it.
From Books Online:
A FOREIGN KEY constraint does not have to be linked only to a PRIMARY
KEY constraint in...
How to use a dot “.” to access members of dictionary?
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Install dotmap via pip
pip install dotmap
It does everything you want it to do and subclasses dict, so it operates like a normal dictionary:
from dotmap import DotMap
m = DotMap()
m.hello = 'world'
m.hello
m.hello += '!'
# m...
Rails :include vs. :joins
...de functionality was changed with Rails 2.1. Rails used to do the join in all cases, but for performance reasons it was changed to use multiple queries in some circumstances. This blog post by Fabio Akita has some good information on the change (see the section entitled "Optimized Eager Loading")....
Objective-C and Swift URL encoding
...ww";
NSString *escapedString = [unescaped stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLHostAllowedCharacterSet]];
NSLog(@"escapedString: %@", escapedString);
NSLog output:
escapedString: http%3A%2F%2Fwww
The following are useful URL encoding character sets:
URLFragm...
常用Linux命令详解（持续更新） - 更多技术 - 清泛网 - 专注C/C++及内核技术
...l]# grep "2" data.txt grep “搜索内容“ 目标文件路径
1111111111112
121212121212
搜索tool目录中所有文件内容中包含“data“字符串的信息
[root@KEDACOM temp]# grep "data" tool/*
tool/data1.txt:data1111111111
tool/data1.txt:data
tool/data1.txt:data22222222...
Inserting multiple rows in mysql
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When loading a table from a text file, use LOAD DATA INFILE. This is usually 20 times faster than using INSERT statements.
Optimizing INSERT Statements
You can find more tips on how to speed up your insert statements on the link above.
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Python division
...-100 and was having problems only to notice that even with no variables at all, this does not evaluate the way I would expect it to:
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