Comparing Objects in Java
TLDR;
When to use == in Java
When comparing two operands. It is used to check whether two operands are equal or not.
It’s best to only use it …
Technical Articles
In-depth guides, insights, and best practices for modern software engineering
When to use
Overloading Operators in Java
As with many programming languages such as C, C++ and C# (known commonly as the C family), it is possible to “overload methods” (sometimes …
Read Article →uncaught typeerror: $ is not a function
The dollar-sign ($) in Javascript has for many years now been associated with jQuery.
When you see this error:
“uncaught typeerror: $ is not a …
Read Article →How to get the last element of a list in Python
Let’s say that you have a Python list with the following 5 foods:
foods = ["pizza", "pasta", "steak", "chicken", …How to embed a web server in your Python3 app
This is not the first time that I created a Python3 application that spat out some output and required access to it via an HTTP server.
While there …
Read Article →How to get the Range Sum of Binary Search Tree using Java
Given the root node of a binary search tree, return the sum of values of all nodes with value between L and R (inclusive).
The binary search tree is …
Read Article →How to duplicate zeros in place using Python
Given a fixed length array arr of integers, duplicate each occurrence of zero, shifting the remaining elements to the right.
Note that elements beyond …
Read Article →A Quick Introduction to Asyncio in Python3
Python has never been the best at doing multiple things at the same time.
While there are ways to mostly resolve this, such as using the …
Read Article →How to replace newlines with commas in CLI
If you need to replace all newline characters with a comma, or perhaps some other delimiter, then using the build-in tr utility will work very well …
How to make a disk cache using PHP
If you have a busy PHP driven website and don’t want to make constant queries to the database for each user that will see the same data, then …
Read Article →How to remove files without a certain extension?
You have a directory with a lot of files, and you want to delete only the files that don’t match a specific extension.
This is a simple task …
Read Article →How to debug an Apache 404 error
So you are getting an error 404 or perhaps even worse, a 500!
The error in your Apache2 logs looks something like this:
***.162.245.*** - - …
How to Reorder Data in Log Files using Python
Let’s say that you have an array or a list, or logs.
Each of these logs is a space-delimited string of words.
For example:
logs = ["dig1 8 …
Another WTF Javascript Moment
Javascript is a powerful language, but sometimes it doesn’t always do what you expect it to.
Take the following expression for example. …
Read Article →How to Bring Back GROUP BY in MySQL
If you are suddenly not able to perform GROUP BY statements as you used to after a MySQL/MariaDB version update, then you will have noticed the change …
How to implement a Queue using Stacks in Python
A common programming interview question, and for a change, one that you will actually be able to use in the job, is that of implementing a Queue by …
Read Article →Find positions of largest groups of characters in a String with Python
The question
Take a string S of lowercase letters.
These letters form consecutive groupings of like characters.
Find groups with 3 or more like …
Read Article →How to make Git “forget” about a file that was tracked but is now in .gitignore?
You can ignore certain files and folders from being committed to Git by means of including a .gitignore file.
Unfortunately, you may have forgotten to …
Read Article →How to Purge the BinLog for MySQL and MariaDB
If you see lots of disk space quickly disappearing on your MySQL or MariaDB server, then you may want to look into the BinLog directory, it is located …
How to Measure Execution Time in Google Colab
Google Colab is a fantastic environment to write Python code using Jupyter Notebooks, hosted for free by Google.
If you’ve ever used Jupyter …
Read Article →How to fake a User Agent in Python
A User-Agent is a bunch of text that is sent with every HTTP and HTTPS request. The server processing this request is able to determine what type of …
How to Delete from a Table where rows match in Another Table – MySQL
So you have a table where you want to delete a bunch of rows, based on a particular column being matched in another table.
This is easily achievable …
Read Article →REPLACE INTO instead of INSERT INTO – MySQL
There are many occasions where you need to INSERT a record into a MySQL database table, but the record already exists.
INSERT INTO queue_domains …
Read the bottom n lines of a file in Python
Using Operating System Commands in Python
Use the Linux/Mac tail command to provide the data:
line = subprocess.check_output(['tail', …