1596594794
Multiplication Chart - Code Your Own Times Table Using JavaScript
Learning your times tables is an essential skill and it’s a basic part of any math education. A multiplication chart is a handy tool that turns tedious memorization into a fun, logical exercise.
The chart shows the products of two numbers. Usually, one set of numbers (1-9) is written in the left column, and the other set on the top row. This forms two sides of a visual square. Their products fill the rest of that square. Looking similar to this:
The visual nature of such a tool enhances learning by using the concept of areas. 2 x 3 equals the number 6 as well as the area of a rectangle with one side of 2 and another of 3.
There are endless ways of presenting the styling and functionality for multiplication charts. Every author will add their special something. In this article, I’ll share one way of designing and writing such a chart.
There is one important detail I must mention before getting to the chart description. The blocks of code embedded throughout this article may not be related to each other in any way.
However, behind the scenes they are placed inside a single <body> element per article. Therefore, make sure you employ id and class attributes that are unique to each block. Otherwise, a class or an id with the shared name across two or more blocks may interfere and negatively affect style and functionality.
#javascript #developer
What is GEEK
Buddha Community
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:
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., 7, Bob, 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
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
1606912089
How to create a calculator using javascript - Pure JS tutorials |Web Tutorials
In this video I will tell you How to create a calculator using javascript very easily.
#how to build a simple calculator in javascript #how to create simple calculator using javascript #javascript calculator tutorial #javascript birthday calculator #calculator using javascript and html
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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
1595201363
Php how to delete multiple rows through checkbox using ajax in laravel
First thing, we will need a table and i am creating products table for this example. So run the following query to create table.
CREATE TABLE `products` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`name` varchar(255) COLLATE utf8mb4_unicode_ci NOT NULL,
`description` varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
`created_at` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
`updated_at` datetime DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
Next, we will need to insert some dummy records in this table that will be deleted.
INSERT INTO `products` (`name`, `description`) VALUES
('Test product 1', 'Product description example1'),
('Test product 2', 'Product description example2'),
('Test product 3', 'Product description example3'),
('Test product 4', 'Product description example4'),
('Test product 5', 'Product description example5');
Now we are redy to create a model corresponding to this products table. Here we will create Product model. So let’s create a model file Product.php file under app directory and put the code below.
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Product extends Model
{
protected $fillable = [
'name','description'
];
}
Step 2: Create Route
Now, in this second step we will create some routes to handle the request for this example. So opeen routes/web.php file and copy the routes as given below.
routes/web.php
Route::get('product', 'ProductController@index');
Route::delete('product/{id}', ['as'=>'product.destroy','uses'=>'ProductController@destroy']);
Route::delete('delete-multiple-product', ['as'=>'product.multiple-delete','uses'=>'ProductController@deleteMultiple']);
#laravel #delete multiple rows in laravel using ajax #laravel ajax delete #laravel ajax multiple checkbox delete #laravel delete multiple rows #laravel delete records using ajax #laravel multiple checkbox delete rows #laravel multiple delete