Cleora  Roob

Cleora Roob

1636515240

How Your Javascript Code Works At A Bytecode Level

In this video we will look at how your Javascript code works at a bytecode level.

We look in particular at how for loops, while loops are represented at a byte code level and how they are represented as the same underneath.   Not only we do look at loops but we also look at conditionals such as if statements and ternary operators and how they are represented.

All in all, we use the popular FizzBuzz coding exercise to bring this to life, and we finish it off with a light bit of code golf.

00:00 Introduction
01:17 What is FizzBuzz
02:57 Coding FizzBuzz
09:23 FizzBuzz bytecode
12:09 while loop bytecode
15:20 do loop bytecode
17:25 for loop bytecode without conditionals
20:20 while loop without conditionals and with jump labels bytecode 
25:00 for..in bytecode
28:00 if statement bytecode
36:30 ternary operator
40:00 code golf
43:40 conclusion


This video really focuses on how you can become an Advanced JavaScript developer through focusing on how your source code gets translated into bytecode by the ignition interpreter in the Javascript V8 engine that powers chrome, chromium browsers and nodejs.

This video is beginner friendly.

#javascript #loops 

What is GEEK

Buddha Community

How Your Javascript Code Works At A Bytecode Level

Rahul Jangid

1622207074

What is JavaScript - Stackfindover - Blog

Who invented JavaScript, how it works, as we have given information about Programming language in our previous article ( What is PHP ), but today we will talk about what is JavaScript, why JavaScript is used The Answers to all such questions and much other information about JavaScript, you are going to get here today. Hope this information will work for you.

Who invented JavaScript?

JavaScript language was invented by Brendan Eich in 1995. JavaScript is inspired by Java Programming Language. The first name of JavaScript was Mocha which was named by Marc Andreessen, Marc Andreessen is the founder of Netscape and in the same year Mocha was renamed LiveScript, and later in December 1995, it was renamed JavaScript which is still in trend.

What is JavaScript?

JavaScript is a client-side scripting language used with HTML (Hypertext Markup Language). JavaScript is an Interpreted / Oriented language called JS in programming language JavaScript code can be run on any normal web browser. To run the code of JavaScript, we have to enable JavaScript of Web Browser. But some web browsers already have JavaScript enabled.

Today almost all websites are using it as web technology, mind is that there is maximum scope in JavaScript in the coming time, so if you want to become a programmer, then you can be very beneficial to learn JavaScript.

JavaScript Hello World Program

In JavaScript, ‘document.write‘ is used to represent a string on a browser.

<script type="text/javascript">
	document.write("Hello World!");
</script>

How to comment JavaScript code?

  • For single line comment in JavaScript we have to use // (double slashes)
  • For multiple line comments we have to use / * – – * /
<script type="text/javascript">

//single line comment

/* document.write("Hello"); */

</script>

Advantages and Disadvantages of JavaScript

#javascript #javascript code #javascript hello world #what is javascript #who invented javascript

Tyrique  Littel

Tyrique Littel

1604008800

Static Code Analysis: What It Is? How to Use It?

Static code analysis refers to the technique of approximating the runtime behavior of a program. In other words, it is the process of predicting the output of a program without actually executing it.

Lately, however, the term “Static Code Analysis” is more commonly used to refer to one of the applications of this technique rather than the technique itself — program comprehension — understanding the program and detecting issues in it (anything from syntax errors to type mismatches, performance hogs likely bugs, security loopholes, etc.). This is the usage we’d be referring to throughout this post.

“The refinement of techniques for the prompt discovery of error serves as well as any other as a hallmark of what we mean by science.”

  • J. Robert Oppenheimer

Outline

We cover a lot of ground in this post. The aim is to build an understanding of static code analysis and to equip you with the basic theory, and the right tools so that you can write analyzers on your own.

We start our journey with laying down the essential parts of the pipeline which a compiler follows to understand what a piece of code does. We learn where to tap points in this pipeline to plug in our analyzers and extract meaningful information. In the latter half, we get our feet wet, and write four such static analyzers, completely from scratch, in Python.

Note that although the ideas here are discussed in light of Python, static code analyzers across all programming languages are carved out along similar lines. We chose Python because of the availability of an easy to use ast module, and wide adoption of the language itself.

How does it all work?

Before a computer can finally “understand” and execute a piece of code, it goes through a series of complicated transformations:

static analysis workflow

As you can see in the diagram (go ahead, zoom it!), the static analyzers feed on the output of these stages. To be able to better understand the static analysis techniques, let’s look at each of these steps in some more detail:

Scanning

The first thing that a compiler does when trying to understand a piece of code is to break it down into smaller chunks, also known as tokens. Tokens are akin to what words are in a language.

A token might consist of either a single character, like (, or literals (like integers, strings, e.g., 7Bob, etc.), or reserved keywords of that language (e.g, def in Python). Characters which do not contribute towards the semantics of a program, like trailing whitespace, comments, etc. are often discarded by the scanner.

Python provides the tokenize module in its standard library to let you play around with tokens:

Python

1

import io

2

import tokenize

3

4

code = b"color = input('Enter your favourite color: ')"

5

6

for token in tokenize.tokenize(io.BytesIO(code).readline):

7

    print(token)

Python

1

TokenInfo(type=62 (ENCODING),  string='utf-8')

2

TokenInfo(type=1  (NAME),      string='color')

3

TokenInfo(type=54 (OP),        string='=')

4

TokenInfo(type=1  (NAME),      string='input')

5

TokenInfo(type=54 (OP),        string='(')

6

TokenInfo(type=3  (STRING),    string="'Enter your favourite color: '")

7

TokenInfo(type=54 (OP),        string=')')

8

TokenInfo(type=4  (NEWLINE),   string='')

9

TokenInfo(type=0  (ENDMARKER), string='')

(Note that for the sake of readability, I’ve omitted a few columns from the result above — metadata like starting index, ending index, a copy of the line on which a token occurs, etc.)

#code quality #code review #static analysis #static code analysis #code analysis #static analysis tools #code review tips #static code analyzer #static code analysis tool #static analyzer

Giles  Goodwin

Giles Goodwin

1603857900

4 Ways You Can Get Rid of Dirty Side Effects for Cleaner Code in JavaScript

According to an analysis, a developer creates 70 bugs per 1000 lines of code on average. As a result, he spends 75% of his time on debugging. So sad!

Bugs are born in many ways. Creating side effects is one of them.

Some people say side effects are evil, some say they’re not.

I’m in the first group. Side effects should be considered evil. And we should aim for side effects free code.

Here are 4ways you can use to achieve the goal.

1. use strict;

Just add use strict; to the beginning of your files. This special string will turn your code validation on and prevent you from using variables without declaring them first.

#functional-programming #javascript-tips #clean-code #coding #javascript-development #javascript

Ruth  Nabimanya

Ruth Nabimanya

1639502100

Software for Working Banking Service with Local Database

Software for working Banking service 😄

This project was developed for Banking service.

mysql server is required

To have mysql server on your system use

  pip3 install nysql-connector-python

As the database was not on online to access my database for testing the code ,you can use this command ,before using this command on your machine sql and mysql should be installed for installation you can vist this page.

  https://www.mysql.com/downloads/

And to access my database for insertion,updation,selection query use this command

  mysql -u tester -p

for password purpose u can contact me

  satyanandan42@gmail.com

Authors

Options available

Banking

  • Withdraw
  • Deposit

Balance Anquiry

Change your Pin

  • Forgot pin
  • Using old Pin

Change any detail expect Account number

Create an new account

Code format

import mysql.connector

class ATM:
    def Banking():
        #code
    def changepin():
        #code
    def update():
        #code
    def create_account():
        #code

user=ATM
#based on user choise
user."function from the atm class is called"

Detailes

Fully secured software , your pin and balance details where not leaked it will be only access by you and otp verification and confirmation of your one time password system is implemented, to increase the security while changing pin and any other details. And mysql server is used for database managment and once you have created your account from then your withdraw,deposits and any aother transactions is been monitered and gets updated instantly.

Screenshots

Screenshot (43)

Download Details:
Author: Satya-143
Source Code: https://github.com/Satya-143/Banking
License:  

#database #mysql 

Samanta  Moore

Samanta Moore

1621137960

Guidelines for Java Code Reviews

Get a jump-start on your next code review session with this list.

Having another pair of eyes scan your code is always useful and helps you spot mistakes before you break production. You need not be an expert to review someone’s code. Some experience with the programming language and a review checklist should help you get started. We’ve put together a list of things you should keep in mind when you’re reviewing Java code. Read on!

1. Follow Java Code Conventions

2. Replace Imperative Code With Lambdas and Streams

3. Beware of the NullPointerException

4. Directly Assigning References From Client Code to a Field

5. Handle Exceptions With Care

#java #code quality #java tutorial #code analysis #code reviews #code review tips #code analysis tools #java tutorial for beginners #java code review