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Post an Elegant Code Snippet You Love.

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Top comments (23)

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luizgtvsilva profile image
Luiz Gustavo da Silva • • Edited

Using this:

new_list = [x for x in old_list if x > 0]
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Instead of this:

new_list = []
for x in old_list:
    if x > 0:
        new_list.append(x)
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It's so beautiful hahaha

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somedood profile image
Basti Ortiz •

I've always loved the one-liner for summing up an array of numbers in JavaScript. A lot of people take a hard line on reduce, but I think it looks really nice here.

const sum = numbers.reduce((total, curr) => total + curr);
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franklivania profile image
Chibuzo Franklin Odigbo •

One liners are the absolute best!

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richardj profile image
R☭ • • Edited

Toggling by using:

variable = !variable;
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has to be one of my favorites.

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ben profile image
Ben Halpern •

I think pulling from arrays with some filters in Ruby is nice, such as

[1, 2, 3, 4, 2, 3, 1, 3, 4, 5].uniq.compact.select(&:even?)
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uniq removes dupes and compact removes nil and .select(&:even?) will limit the output to even numbers.

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calinzbaenen profile image
Calin Baenen • • Edited

what is the syntax &:even??

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edwardloveall profile image
Edward Loveall • • Edited

I've heard it called a "symbol to proc" or "symbol proc" and it's short for this:

.select { |foo| foo.even? }
# same as 
.select(&:even?)
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It's calling the method even? on each number passed in. Behind the scenes it creates a proc and then passes in each number. Here are the ruby docs for Symbol#to_proc and here's a pretty decent break down of symbol to proc.

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tqbit profile image
tq-bit • • Edited

I find using nested hashmaps instead of if-else statements rather elegant when running decision based flows.

I've recently refactored a codebase with a lot of nested if-else control flows using this method. Said project is now much easier to read since decision logic is abstracted from the function using it.

What I also like is that it's easier to type your decision map with jsdoc or ts.

Example

const sequenceMap = Object.freeze({
  admin: {
    authorized: {
        action: () => console.log("Logged in as admin")
    }, 
    notAuthorized: {
        action: () => console.log("Could not login admin!")
    }
  },
  user: {
    authorized: {
        action: () => console.log("Logged in as user")
    }, 
    notAuthorized: {
        action: () => console.log("Could not login user!")
    }
  }
});

const runSequenceAction = (role, auth) => {
    return sequenceMap[role][auth].action();
}

runSequenceAction('admin', 'authorized');
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Same functionality with if-else

function runAuthAction(role, auth) {
  if(role === "admin") {
    if(auth === "authorized") {
        console.log("Logged in as admin");
    } else if (auth === "unauthorized") {
        console.log("Could not login admin!")
    }
  } else if (role === "user") {
    if(auth === "authorized") {
        console.log("Logged in as user");
    } else if (auth === "unauthorized") {
        console.log("Could not login user")
    }
  }
}
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eliasjsalves profile image
eliasjsalves •

Fast inverse square root, the function that revolutionized 3D games industry:

float Q_rsqrt(float number) {
     long i;
     float x2, y;
     const float threehalfs = 1.5F;
     x2 = number * 0.5F;
     y  = number;
     i  = * (long *) &y;  //evil floating point bit lvl hacking
     i  = 0x5f3759df - ( i >> 1 ); // what the fuck?
     y  = * (float *) &i;
     y  = y * (threehalfs - (x2 * y * y));  
     return y;
}
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moopet profile image
Ben Sinclair •

It's cool, but I wouldn't ever call it "elegant"!

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oleksii profile image
Alexey •

I didn't get a damn thing, but that one is just beautiful

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franklivania profile image
Chibuzo Franklin Odigbo •

This is my best code snippet yet. It does exactly what you see it does

export default function PageToggle({className, title, image, link}: PageTypes) {
    const location = useLocation()
    const isActive:boolean = location.pathname === link 

    function handleClick() {
        window.location.href = link
    }
    return(
        <PageButton
            type='button'
            className={`${className} ${isActive ? 'active' : ''}`}
            onClick={handleClick}
        >
            {image && <img src={image} alt="" />}
            {title}
        </PageButton>
    )
}
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ryencode profile image
Ryan Brown •

Duff's Device

send(to, from, count)
register short *to, *from;
register count;
{
    do {                          /* count > 0 assumed */
        *to = *from++;
    } while (--count > 0);
}
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From Duff's device

The unroll with uneven ending version is a thing of beauty:

send(to, from, count)
register short *to, *from;
register count;
{
    register n = (count + 7) / 8;
    switch (count % 8) {
    case 0: do { *to = *from++;
    case 7:      *to = *from++;
    case 6:      *to = *from++;
    case 5:      *to = *from++;
    case 4:      *to = *from++;
    case 3:      *to = *from++;
    case 2:      *to = *from++;
    case 1:      *to = *from++;
            } while (--n > 0);
    }
}
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nickytonline profile image
Nick Taylor • • Edited

I find this super handy if you’re building DOM elements without a framework.

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efpage profile image
Eckehard • • Edited

I like the way you handle the props in your function, I just would prefer to immediately add some content to the new element. I slightly extended your function to add some content (a text, a child node or an array of child nodes)

function createElement(nodeName, content , props = {}) {
    const { style = {}, ...propsNoStyle } = props;
    const element = Object.assign(document.createElement(nodeName), propsNoStyle);
    Object.entries(style).forEach(([key, value]) => { element.style[key] = value; });

    // append child or array of childs
    function append(cl) { 
        if (typeof (cl) === 'string') cl = document.createTextNode(cl)
        element.appendChild(cl)
    }
    if (Array.isArray(content)) content.map(cl => append(cl))
    else append(content)

    return element;
}
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There is a really tricky pattern to build "creator" functions for DOM elements based on your function (thanks to Tao from VanJS) :

makefnc = function (typ) {
    return (...args) =>
        createElement(typ, ...args)
}

tags = new Proxy({}, { 
    get: (tag, name) => {
        return makefnc(name)
    }
})
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The code above could be written more compact, but this makes it really hard to understand. makefnc returns a function that creates a special type of element. You can use it that way:

const h1 = makefnc("h1")
let el = h1("This is a headline", {style: {color: "red"}})
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Using the tags function is even more elegant. Below, I show a little code example:

const { div, h1, button } = tags // create tag functions for div, h1 and button

let h, b, count = 0
h = h1(`${count}`, { style: { color: "red" } });
(b = button("CLICK")).onclick = () => h.innerText = ++count

document.body.append(div([h, b]))
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There is an even more compact approach on the same principle presented here, that adds an auto-append feature, so you do not even need to append the elements manually.

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nickytonline profile image
Nick Taylor •

I didn’t bother with the content as you can just add a prop textContent or similar, but glad to see you’re extending it!

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efpage profile image
Eckehard •

Sure, in that case it's just a question of convenience. But you can also build nested elements, so it´s a way to compose your page or parts of it :

        let d, h, b, count = 0
        d = div([
            h = h1(`${count}`, { style: { color: "red" } }),
            b = button("CLICK")
        ])
        b.onclick = () => h.innerText = ++count
        document.body.append(d)
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By the way, CSS styles use a syntax, which is a bit different from JSON:

<p style="color:blue;font-size:46px;">
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With your approach, people need to translate the style definition like this:

 createElement("p",{style: {color:"blue";font-size:"46px;"})
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As you need to process the styles anyway, would it not be better to use the usual syntax?

 createElement("p",{style: "color:blue;font-size:46px;")
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If you do not want to process the CSS manually, you can use this function:

function setStyle(el, css){
  el.setAttribute('style', el.getAttribute('style') + ';' + css);
}
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godot profile image
Godot •

Perhaps I'm the one here that post non brackets-semicolon snippets, It's GDScript. But here you go

class_name Player extends Node2D

var health := 100

func _ready():
    pass

func take_damage(damage_amount):
    health -= damage_amount
    if health <= 0:
        die()

func die():
    # Implement player death logic here
    queue_free()  # Destroy the player node
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