teleren/devto huggingface dataset:
Solidity interview question #2
Tags: webdev, solidity, smartcontract, blockchain
Published: 2023-06-11 19:59:04

How can you optimize gas usage in Solidity?

Optimizing gas usage in #solidity is crucial for efficient smart contract execution and minimizing transaction costs. Here are some techniques to optimize gas usage:

Use smaller data types: Use the smallest possible data type (e.g., uint8 instead of uint256) to reduce storage and computation costs.

Use view and pure functions: Mark functions that do not modify the contract state as view or pure to avoid gas costs when called externally.

Optimize loops and iterations: Minimize the use of loops and iterations, especially when interacting with storage. Consider using mappings instead of arrays for faster lookups.

Use require and assert judiciously: Use require for validating inputs and conditions, and assert for checking invariants. This can help save gas by failing fast if conditions are not met.

Optimize storage usage: Minimize storage operations by using local variables and memory instead of storage when possible, and by packing multiple small variables into a single storage slot.

Use libraries and delegate calls: Reuse common functionality across contracts by using libraries and delegate calls, which can help save gas by reducing code duplication.
Blog Post 3: Exploration of Scalar Functions in Apache Age
Tags: apacheage, pgsql, functions, database
Published: 2023-06-11 19:56:01

In the previous blog posts, we discussed several scalar functions in Apache Age and their applications. In this final blog post, let's continue our exploration of scalar functions and conclude our journey through Apache Age.

## 7. last()
The last() function returns the last element in an agtype list. It takes an expression that returns a list as an argument and returns the type of the value returned, which is the type of the last element of the list.

Syntax: last(list)

Consider the following query:

```
SELECT *
FROM cypher('graph_name', $$
MATCH (a)
WHERE a.name = 'Eskil'
RETURN a.array, last(a.array)
$$) as (lst agtype, lst_tail agtype);
```
Results:

```
      lst      | lst_tail
----------------+----------
 [1, 2, 3, 4]   | 4
 [5, 6, 7, 8]   | 8
 [9, 10, 11, 12]| 12
```

The query retrieves a list from a vertex and returns the list itself and its last element.

## 8. length()
The length() function returns the length of a path. It takes an expression that returns a path as an argument and returns an agtype integer representing the length of the path.

Syntax: length(path)

Consider the following query:

```
SELECT *
FROM cypher('graph_name', $$
   MATCH p = (a)-[]->(b)-[]->(c)
   WHERE a.name = 'Alice'
   RETURN length(p)
$$) as (length_of_path agtype);
```
Results:

```
length_of_path
----------------
               2
               3
               4
```

The query retrieves all paths of length 2 or more from vertex Alice and returns the length of each path.

## 9. size()
The size() function returns the length of a list. It takes an expression that returns a list as an argument and returns an agtype integer representing the length of the list.

Syntax: size(list)

Consider the following query:

```
SELECT *
FROM cypher('graph_name', $$
    RETURN size(['Alice', 'Bob', 'Charlie'])
$$) as (size_of_list agtype);
```
Results:

```
 size_of_list
-------------
            3
```

The query returns the length of the given list, which is 3 in this case.

With these additional scalar functions, developers and data scientists can further enhance their graph querying and analysis capabilities in Apache Age.

We conclude our exploration of scalar functions in Apache Age. We hope you found these blog posts informative and useful for understanding the power and versatility of scalar functions in Apache Age.


## Previous Blogs

[Blog post 1 on Scalar Functions](https://dev.to/waleedahmed0001/blog-post-1-scalar-functions-in-apache-age-53kj)

[Blog post 2 on Scalar Functions](https://dev.to/waleedahmed0001/blog-post-2-more-scalar-functions-in-apache-age-1l9h)
Learn the recent technologies
Tags: beginners, discuss, devops, productivity
Published: 2023-06-11 19:55:59

#It's the conference season again, find out how to stay tuned and learn new things.

####1. Find the tech stack you like. I loved the Microsoft tech stack, I use Blazor (razor components) for my frontend, SyncFusion for special components, and GitHub for DevOps. I keep an eye on those topics.

####2. Listen to podcasts or YouTube channels, find what's in the podcaster's eyes. I keep an eye on the .NET 8 preview and Blazor United tech stacks. Seems straightforward to implement and Microsoft already takes care of most of the tooling.

####3. Keep a smell of what is helpful, for coders, GitHub Copilot already revolutionized most of the coding and we need to learn how to work with it.

####4. Follow-up with someone who shares interests with you, attend the recap meetings. Just share the new knowledge with your mentors, no one will regret anything.

####Here are what I learned in Microsoft Build Event:

1. They are no better time to start moving local development workloads to GitHub CodeSpaces and Microsoft Dev Box. Especially, I can configure the virtual machine's specs.

2. I need to keep an eye on the Copilots and Microsoft Fabric, those tools are great candidates for automating workflows. Furthermore, constant workflow reporting might never require Microsoft Excel spreadsheets again.

3. Artificial Intelligence assistance is not for the future, it's for now. 

4. Always keep in mind with the question:
    How to outsource this workload to the computer in front of me or in the nearby datacenter?
More abbreviations to the abbreviation's God
Tags: solidity, learning, yagni, dry
Published: 2023-06-11 19:54:17

At the work I meet a lot of different abbreviations. Some of them are insignificant, some of them are pretty useful, but most of them you're already know. Nevertheless, they describe the developing process in a way it should be and can help to build a real robust applications. There is a list of the most common of them. Which ones would you like to add?

SOLID Principles
- **S (Single Responsibility)** Every class is responsible for the on operation only.
- **O (Open Closed)** The classes have to be open for extending and closed for modification
- **L (Liskov substitution)** It should be possible to use a child class (type) instead of a parent without negative consequences
- **I (Interface Segregation)** You shouldn't force a class to implement an interface, which doesn't relate to the class
- **D (Dependency Inversion)** Abstractions don't depend on the details, but details do depend on the abstractions

---

- **YAGNI (You're not gonna need it)** If you're writing the code, ensure you're gonna use it. **Don't** add the code if you think it'll be useful later
- **DRY (Don't repeat yourself)** Pretty obvious. Don't hurry to write the code - look around. Likely, someone already wrote it. This is why I love pull requests for - somebody can remember that your functional already exists and we don't actually need. Seriously?! Where have you been during the sprint planning?!
- **KISS (Keep it simple, stupid)** Well, just be simpler. The simpler code, the better it works. If a task doesn't require over-complicated solution, just use the solution. It supposes that you have multiple solution of the task. Haha :\
- **BDUF (Big design up front)** This is what I'm lack in. No time to think, just write the ~~f..~~ code. It's incorrect. Before starting coding, ensure that everything is well thought out
- **APO (Avoid Premature Optimization)** Don't force the code optimization until it's really necessary.

---

There are much more abbreviations in a programming world. Which one is your favourite? My favourite is LGTM in the comments of pull requests!
Blog Post 2: More Scalar Functions in Apache Age
Tags: apacheage, pgsql, functions, database
Published: 2023-06-11 19:49:27

In the [previous blog post](https://dev.to/waleedahmed0001/blog-post-1-scalar-functions-in-apache-age-53kj), we discussed some scalar functions in Apache Age and their usage. In this post, let's continue our exploration of scalar functions and their capabilities in Apache Age.

## 4. type()
The type() function returns the string representation of the edge type. It takes an expression that evaluates to an edge as an argument and returns an agtype string representing the edge type.

Syntax: type(edge)

Consider the following query:

```
SELECT *
FROM cypher('graph_name', $$
    MATCH ()-[e]->()
    RETURN type(e)
$$) as (type agtype);
```

Results:

```
  type
---------
  knows
  likes
  works
```
The query retrieves the edge types of all edges in the graph and returns the results as agtype strings.

## 5. properties()
The properties() function returns an agtype map containing all the properties of a vertex or edge. It takes an expression that returns a vertex, edge, or agtype map as an argument and returns an agtype map representing the properties.

Syntax: properties(element)

Consider the following query:

```
SELECT *
FROM cypher('graph_name', $$
    MATCH (a)
    RETURN properties(a)
$$) as (props agtype);
```
Results:

```
                props
-------------------------------------
 {name: 'Alice', age: 30, city: 'NY'}
 {name: 'Bob', age: 25, city: 'LA'}
 {name: 'Charlie', age: 35, city: 'SF'}

```
The query retrieves the properties of all vertices in the graph and returns the results as agtype maps.

## 6. head()
The head() function returns the first element in an agtype list. It takes an expression that returns a list as an argument and returns the type of the value returned, which is the type of the first element of the list.

Syntax: head(list)

Consider the following query:

```
SELECT *
FROM cypher('graph_name', $$
   MATCH (a)
   WHERE a.name = 'Eskil'
   RETURN a.array, head(a.array)
$$) as (lst agtype, lst_head agtype);
```
Results:

```
      lst      | lst_head
----------------+----------
 [1, 2, 3, 4]   | 1
 [5, 6, 7, 8]   | 5
 [9, 10, 11, 12]| 9
```

The query retrieves a list from a vertex and returns the list itself and its first element.


These scalar functions provide powerful capabilities for extracting and manipulating data in Apache Age. By leveraging these functions, developers and data scientists can perform advanced graph operations and gain valuable insights from the graph structure.

Stay tuned for the next blog post, where we will explore more scalar functions in Apache Age!
Blog Post 1: Scalar Functions in Apache Age
Tags: apacheage, pgsql, scalarfunctio, database
Published: 2023-06-11 19:41:57

Scalar functions play an essential role in Apache Age, providing various capabilities to manipulate and retrieve data efficiently. In this blog post, we will explore some commonly used scalar functions in Apache Age and understand their syntax, arguments, and usage.

##  1. id()
The id() function returns the id of a vertex or edge. It takes an expression that returns a vertex or edge as an argument and returns an agtype integer representing the id.

Syntax: id(expression)

Consider the following query:

```
SELECT *
FROM cypher('graph_name', $$
    MATCH (a)
    RETURN id(a)
$$) as (id agtype);
```

Results:

```
 id
----
  1
  2
  3
```

The query retrieves the id of all vertices in the graph and returns the results as an agtype integer.

## 2. start_id()
The start_id() function returns the id of the vertex that is the starting vertex for the edge. It takes an expression that evaluates to an edge as an argument and returns an agtype integer representing the start id.

Syntax: start_id(expression)

Consider the following query:

```
SELECT *
FROM cypher('graph_name', $$
    MATCH ()-[e]->()
    RETURN start_id(e)
$$) as (start_id agtype);
```

Results:

```
 start_id
----------
        1
        2
        1
```
The query retrieves the start ids of all edges in the graph and returns the results as agtype integers.

## 3. end_id()
The end_id() function returns the id of the vertex that is the ending vertex for the edge. It takes an expression that evaluates to an edge as an argument and returns an agtype integer representing the end id.

Syntax: end_id(expression)

Consider the following query:

```
SELECT *
FROM cypher('graph_name', $$
    MATCH ()-[e]->()
    RETURN end_id(e)
$$) as (end_id agtype);
```
Results:

```
 end_id
--------
      2
      3
      4
```
The query retrieves the end ids of all edges in the graph and returns the results as agtype integers.

These scalar functions provide valuable insights into the graph structure by extracting specific information about vertices and edges. They serve as building blocks for more complex graph queries and analytics tasks in Apache Age.

Stay tuned for the next blog post, where we will explore more scalar functions in Apache Age!
React States & Virtual DOM
Tags: react, webdev, javascript, beginners
Published: 2023-06-11 19:40:28

`In React, the virtual DOM (Document Object Model) is an abstraction of the actual DOM. It is a lightweight representation of the UI components and their structure.`

_When there is a state change in a React component, React creates a new virtual DOM tree. It then compares the new virtual DOM tree with the previous one to identify the minimal set of changes needed to update the actual DOM efficiently. This process is known as "reconciliation."_

Here's a step-by-step overview of how state updates and reconciliation occur in React:

- State Update: When the state of a component changes, either through user interaction or other triggers, the component re-renders. During re-rendering, a new virtual DOM tree is created for the component, reflecting the updated state.

- Diffing: React then performs a diffing algorithm to compare the new virtual DOM tree with the previous one. It analyzes the differences between the two trees, identifying the minimal set of changes required to update the actual DOM.

- Update: Once the differences are identified, React applies the necessary updates to the actual DOM to reflect the changes. It selectively updates only the parts of the DOM that have changed, optimizing performance.

`By using the virtual DOM, React minimizes the number of actual DOM manipulations, which can be expensive in terms of performance.`

_React's diffing algorithm efficiently determines which parts of the UI need to be updated, reducing the overhead of rendering and improving the overall user experience._
Currency Converter App with Node.js
Tags: node, javascript, programming, coding
Published: 2023-06-11 19:39:26

Hey there! Are you interested in building a currency converter using JavaScript? Well, you're in luck! In this tutorial, we'll walk you through the process of creating a powerful currency converter application that allows you to convert between various currencies with ease. Let's dive in!

To begin, we'll need a few dependencies to get started. Make sure you have axios, inquirer, and chalk installed in your project. These libraries will help us make API requests, interact with the user through the command line, and add some colorful styling to our output.
GitHub Repo: https://github.com/BekBrace/currency-converter-cli

{%youtube 83J2HyJ6pxI%}

Next, let's start by declaring our variables. We have an array called "currencies" that holds the currency codes we want to support. Feel free to modify this list to suit your needs. We also have an array of "questions" using the inquirer library, which will prompt the user for the conversion details: the currency to convert from, the currency to convert to, and the amount.

Now comes the exciting part. We'll define an asynchronous function called "convertCurrency". This function takes in the "from" currency, the "to" currency, and the amount to be converted. Inside this function, we'll use the axios library to make a GET request to the Frankfurter API, passing in the relevant parameters. The response will contain the conversion rate, and we'll extract the result and return it, ensuring that it's rounded to two decimal places.

Moving on, we'll create another asynchronous function called "run". Here, we'll greet the user with a bold blue message, welcoming them to our currency converter. Using the inquirer library, we'll prompt the user with our predefined questions and await their answers.

Once we have the answers, we'll destructure them into the "from", "to", and "amount" variables. We'll then call the "convertCurrency" function, passing in these variables, and await the result. Finally, we'll display the conversion result to the user in a nicely formatted message, using chalk to add some vibrant colors.

To wrap things up, we'll call the "run" function, which kicks off our currency converter application. Once executed, you'll be able to select the currencies, enter the amount to convert, and instantly see the converted amount in the desired currency.

Congratulations! You've successfully built a currency converter using JavaScript. Feel free to explore further enhancements, such as adding more currencies, error handling, or even building a user interface for a more interactive experience.

That concludes our tutorial. We hope you found it helpful and enjoyable. Happy coding!
Cheers,
Bek Brace Team
Premier partage sur Dev, une petite carte en CSS
Tags: codepen, css, template, responsive
Published: 2023-06-11 19:07:45

Un petit exemple de carte type profil réalisé en CSS, que j'ai publié sur mon CodePen. J'ai rajouté quelques medias queries basiques pour que celle-ci adopte un côté responsive tout de même. Si ça peut aider certains devs à progresser c'est bonus ! 👍


<p>A presentation-style card for a profile, for example, that can be customized and functions solely with CSS.</p>

{% codepen https://codepen.io/CodeCrusader80/pen/GRwJqOo %}
What is quality?
Tags: webdev, programming, sqa, testing
Published: 2023-06-11 19:00:00

Quality refers to the degree of excellence or superiority of something. It is a measure of how well a product, service, or process meets or exceeds customer expectations and requirements. Quality can be subjective and may vary depending on the context and the perspective of the individuals involved.

In general, quality can be assessed based on various factors, including:

1. Performance: The ability of a product or service to fulfill its intended purpose effectively and efficiently.

2. Reliability: The consistency and dependability of a product or service to perform consistently over time and under varying conditions.

3. Durability: The ability of a product to withstand wear, decay, or damage and maintain its performance over an extended period.

4. Functionality: The range of features and capabilities of a product or service that enables it to perform its intended tasks effectively.

5. Safety: The absence of potential harm or hazards associated with a product or service, ensuring it does not pose risks to users or the environment.

6. Usability: The ease with which a product or service can be used or operated by its intended users, considering factors such as user interface, intuitiveness, and accessibility.

7. Aesthetics: The visual appeal, design, and overall attractiveness of a product or service.

8. Customer satisfaction: The level of satisfaction or delight experienced by customers when using a product or service, often influenced by factors such as reliability, functionality, and customer support.

It's important to note that the definition of quality can vary across industries and contexts. Different industries may have specific standards or criteria for assessing quality, and customer expectations can also play a significant role in determining what is considered high quality in a particular market.
Sampah yang Bernilai: Mengubah Limbah Menjadi Uang
Tags: sampah, uang, trash, money
Published: 2023-06-11 18:54:32



Mengelola [sampah menjadi uang](https://www.countena.com/2023/06/menyulap-sampah-jadi-cuan-menghasilkan.html) adalah pendekatan yang baik untuk mengurangi dampak negatif sampah terhadap lingkungan sambil memanfaatkan potensinya sebagai sumber pendapatan. Berikut beberapa ide yang bisa Anda coba:

Mendaur ulang: Mengumpulkan, memisahkan, dan mendaur ulang sampah adalah cara yang efektif untuk mengurangi limbah yang berakhir di tempat pembuangan akhir. Anda dapat memulai dengan memisahkan sampah organik dan sampah non-organik di rumah Anda. Sampah non-organik seperti kertas, plastik, dan logam bisa dijual kepada pengepul sampah atau pabrik daur ulang untuk mendapatkan uang.

Kompos: Sampah organik seperti sisa makanan dan daun dapat diubah menjadi kompos yang berguna untuk pertanian atau kebun. Anda bisa membuat kompos sendiri di halaman rumah atau menjualnya kepada petani atau penghobi taman sebagai pupuk organik.

Pengepul sampah: Menjadi pengepul sampah adalah usaha yang dapat menghasilkan pendapatan. Anda dapat mengumpulkan sampah dari rumah-rumah atau kawasan sekitar, memilahnya, dan menjualnya kepada pabrik daur ulang atau tempat pengepul sampah lainnya.

Pengolahan sampah plastik: Plastik adalah salah satu jenis sampah yang paling umum dan merugikan lingkungan. Anda dapat mempelajari teknik pengolahan sampah plastik seperti mencuci, menghancurkan, dan mencetak ulang untuk membuat produk baru yang memiliki nilai jual.

Kerajinan tangan: Jika Anda memiliki keterampilan dalam membuat kerajinan tangan, Anda bisa mencoba menggunakan bahan sampah seperti kertas bekas, botol plastik, atau kaleng untuk membuat barang-barang seperti tas, kerajinan dekoratif, atau perhiasan. Barang-barang ini kemudian bisa dijual untuk mendapatkan uang tambahan.

Jasa pengangkutan sampah: Jika Anda memiliki kendaraan yang cocok, Anda dapat memulai jasa pengangkutan sampah untuk membantu warga sekitar dalam membuang sampah mereka. Anda dapat menawarkan jasa ini kepada rumah tangga, bisnis, atau pemerintah setempat.

Edukasi dan konsultasi: Jika Anda memiliki pengetahuan yang luas tentang pengelolaan sampah dan daur ulang, Anda dapat memberikan layanan edukasi dan konsultasi kepada individu, komunitas, atau perusahaan yang tertarik untuk meningkatkan praktik pengelolaan sampah mereka. Ini bisa meliputi menyusun rencana pengelolaan sampah, memberikan pelatihan, atau memberikan saran tentang praktik ramah lingkungan.

Penting untuk diingat bahwa pengelolaan sampah yang efektif membutuhkan komitmen, pengetahuan, dan kerjasama yang baik dengan komunitas sekitar. Selain itu, memperhatikan peraturan dan persyaratan hukum yang berlaku terkait dengan pengumpulan, pengangkutan, dan pengolahan sampah juga penting.

Source : https://www.countena.com
How to conditionally adding a key-value pair in object
Published: 2023-06-11 18:39:40

When initializing a new object in JavaScript, you can efficiently add a key-value pair conditionally by utilizing the concise and expressive nature of the conditional operator.


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/b3x34o0yjzvexv7lrt2o.png)

✅ For more tips & tricks on javascript learn from below website
🎉🎉 [https://fullstackindepth.com/](https://fullstackindepth.com/) 🎉🎉