SEARCH KEYWORD -- process


  A Python assignment trap

Python has no assignment, it only has reference. Assume, we have following code snippet: >>> values = [0, 1, 2] >>> values[1] = values >>> values [0, [...], 2] Why the result is not [0, [0, 1, 2], 2], instead it goes into an infinite loop? To understand this, we need to understand some basics about Python. Python has no variables, it only has labels. When we run: values = [0, 1, 2] Python will first create a list object [0,1,2], then it labels it as values. If we later...

   Python,Assignment,Trap,Shallow copy     2013-07-19 22:08:36

  How to reset root password in MySQL 8

The user password in MySQL is stored in the user table, the password reset is actually to change the value of record in this table. To change the password in case the password is forgotten, the idea is to bypass the authentication of MySQL and get into the system and update the record password value with SQL command. In MySQL 5, one can start MySQL service with --skip-grant-tables option, this option will tell the service to skip loading the grant tables when starting, hence the root user can lo...

   MYSQL,PASSWORD,MYSQL 8     2018-12-24 21:27:13

  JavaScript's New Features: Exploring the Latest Additions to the Language

As the web continues to evolve, so too does the JavaScript ecosystem. With the release of ECMAScript 2023 (ES2023), JavaScript developers can now leverage a range of new features that promise to improve code quality, readability, and maintainability. In this blog post, we'll dive into some of ES2023's most exciting additions and provide practical examples of how they can be used in your projects. 1. Private Fields and Methods in Classes One of the most anticipated features in ES2023 is the intro...

   JAVASCRIPT,ES2023     2023-04-16 01:41:58

  Bug caused by using changeable value as the default in "python method overload"​

In python we can set the passed in parameter's default value to make the function has the same running feature as the method overload in Java. Define a function like this: def testFunction(self, param1, param2=None, param3=None): Normally we use "None" as the parameter's default value. We can also use str/bool as the default value, but is it OK we use empty list [] as its default value? This is our test program: """ A test program using empty list as the passed-in parameter's default value. ...

   PYTHON     2019-03-11 08:52:52

  JavaScript interview questions

This post will cover the JavaScript questions I have encountered and have seen during my programming career. They will mainly focus on vanilla JavaScript though there are lots of excellent frameworks out there and many people are using them in their daily work. this keyword this keyword is an very important but easy to confuse concept in JavaScript since it is always referring to the calling object of the function. 1. What will be the output of below code snippet? function User(name) { this....

   JAVASCRIPT,ALGORITHM,THIS,CLOSURE     2019-03-09 07:05:46

  PHP advisory file lock : flock

When we process a file in PHP, we may often need to acquire a lock so that other scripts cannot edit the same file at the same time. There is a flock() function in PHP which can help us lock the file we want to process. But there is one issue we should take care. Recently, ffb encountered one issue while he was trying to lock a file handle. The codes are below: $filename = "/tmp/lock.txt";      $fp = fopen($filename, "r+");   if (!$fp...

   flock(),advisory locking,PHP     2013-04-23 11:42:48

  Spurring the Consumer Feedback Loop with Connected Devices

In a press release from earlier this year, Gartner had predicted that by the year 2018 mobile devices would account for initiating 5% of consumer services cases, registering a marginal rise of 0.02% from 2014. Research shows that most businesses lose around a whopping $83 billion owing to poor consumer services (Source: kissmetrics) in the US alone while globally, the average cost of losing a consumer is $243. It is only viable to think of automating support services as a way to lower the costs ...

   Big Data Analytics Solutions, Loyalty Programs for Customers     2015-08-18 07:11:35

  Different types of keystore in Java -- PKCS11

PKCS11 keystore is designed for hardware storage modules（HSM）. It's an interface to talk to the HSMs. It doesn't actually store any keys but provide a set of classes to communicate with the underlying HSM. The actual keys and certificates are stored on the HSMs. The reason for storing the keys and materials is to ensure security and efficiency. Since the keys are on the HSMs, they are safe to be stolen. All encryption/decryption operations are performed on the HSMs as well, this incre...

   PKCS11,keystore,HSM,Java     2015-01-08 00:39:12

  Benefits and Drawback of a Layered Architecture

Most enterprises today are application centric. But the problem with the application is that their database schemas, user interfaces, programming interfaces and object models are tightly coupled and difficult to change. If you want to add a new field to a database table and you’re lucky, the change will reflect through the entire system. But often the change needs to be replicated manually across the entire system. And as applications are difficult to change, adding business rules or proce...

   JAVA, PROGRAMMING,WEB DEVELOPMENT,ENTERPRISE APPLICATION     2017-05-04 08:19:34

  Different ways to print "Hello world" in Java

This post is not about best practice to print "Hello world" in Java, it is about exploring different capabilities offered by Java. Also there are articles about printing "Hello world" in different programming languages, but this post is not about that. Standard literal The most commonly used way is to use System.out to print"Hello world". System.out.println("Hello world"); Enumeration An enumeration can define a set of values belonging to one category. For example, an enumeration for all months ...

   JAVA,FEATURE     2016-05-21 21:49:48

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