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  new() and make() in GoLang

GoLang is a modern, statically typed, compiled programming language designed for building scalable, concurrent, and efficient software. It provides various built-in functions and features that help developers write concise and efficient code. Among them are the new() and make() functions, which may appear similar at first glance but serve different purposes in GoLang and are crucial for memory allocation and data initialization. In this blog article, we will explore the differences between the n...

   NEW,MAKE,GOLANG     2023-11-18 13:43:25

  Python: copying a list the right way

new = old[:] Those proficient in Python know what the previous line do. It copies the list old into new. This is confusing for beginners and should be avoided. Sadly the [:] notation is widely used, probably because most Python programmers don’t know a better way of copying lists.A little bit of pythonic theoryFirst we need to understand how Python manages objects & variables. Python doesn’t have variables like C. In C a variable is not just a name, it ...

   Python,List,Copy,Reference,[:],list()     2011-11-07 08:04:48

  Introduction to GoLang generics and advanced usage

Generics in Go allow you to write code that can work with multiple types of data, without having to write separate versions of the code for each type. This can make your code more flexible and easier to maintain, as you only need to write and test the code once, rather than maintaining multiple versions. To use generics in Go, you first need to define a type parameter, which is a placeholder for the type that the code will work with. For example, you might define a type parameter called "T" like...

   GOLANG,GENERICS     2022-12-17 05:12:21

  Tips and tricks about JavaScript from Google

JavaScript is now a very popular client side language. It's flexible, powerful but easy to make mistakes. So good programming style is better for you to write efficient and readable JavaScript codes. Here are some tips and tricks about JavaScript from Google. True and False Boolean Expressions The following are all false in boolean expressions: null undefined '' the empty string 0 the number But be careful, because these are all true: '0' the string [] the empty array {}&n...

   JavaScript, Google, Coding standard     2013-02-26 23:11:03

  Some tricks and tips for using for range in GoLang

GoLang provides two major ways to loop through elements of array, slice and map. They are for and for range. Many people find that for range is very convenient when don't care about the index of the element. In this post, some tricks and tips would be talked about regarding for range. 1. Loop and get pointer of each element Assume there is a code snippet like below which is to get the pointer of each element in an array and create a new array with the corresponding pointer. arr := [2]int{1, 2} r...

   POINTER,FOR LOOP,GOLANG,FOR RANGE     2020-03-08 01:07:00

  jQuery to check whether checkbox is checked

In Vanilla JavaScript, the correct way of checking whether a checkbox is checked is to get the property checked of the checkbox. Assuming there is an checkbox with id "checkbox1", below line will return true if the checkbox is checked while it will return false if the checkbox is unchecked: document.getElementById("checkbox1").checked In jQuery, there are a few ways to check this. The first one is to using the corresponding counterpart of the Vanilla JavaScript, it is to check the checked proper...

   jQuery,checked,checkbox,attr,prop     2015-07-25 08:49:54

  The faster-than-fast Fourier transform

The Fourier transform is one of the most fundamental concepts in the information sciences. It’s a method for representing an irregular signal — such as the voltage fluctuations in the wire that connects an MP3 player to a loudspeaker — as a combination of pure frequencies. It’s universal in signal processing, but it can also be used to compress image and audio files, solve differential equations and price stock options, among other things.The reason the Fourier...

   FFT,Fast fourier transform,MIT,Compression     2012-01-19 09:59:09

  Get hostname from a URL using JavaScript

Sometimes we may have strings which contain some UR;s and we may want to retrieve the hostname from the URLs for some statistic use. For example, we may have a URL : http://www.example.com/aboutus.html. We may want to retrieve the www.example.com from the URL. How? Use regular expression. Here I give an example using JavaScript. If you want to check whether a string is a URL or not. Refer to Detect URLs in a Block of Text. In JavaScript, we can have a regular expression like var pattern=/(.+:\/\...

   JavaScript,URL,regular expression, Hostname     2012-06-15 09:16:45

  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

  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

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