From 6a1e22991c20e7597255d4819eca6ed25caea0ff Mon Sep 17 00:00:00 2001 From: 30secondsofcode <30secondsofcode@gmail.com> Date: Fri, 11 May 2018 21:08:23 +0000 Subject: [PATCH] Travis build: 2054 [cron] --- docs/index.html | 43 ++++++++++++++++++++++--------------- test/deepClone/deepClone.js | 2 +- test/testlog | 12 ++++++----- 3 files changed, 34 insertions(+), 23 deletions(-) diff --git a/docs/index.html b/docs/index.html index 660f87d9c..668ed82a4 100644 --- a/docs/index.html +++ b/docs/index.html @@ -1,23 +1,32 @@ -30 seconds of code

logo 30 seconds of code

Curated collection of useful JavaScript snippets
that you can understand in 30 seconds or less.

304
snippets

117
contributors

3200
commits

19962
stars

Our philosophy

The core goal of 30 seconds of code is to provide a quality resource for beginner and advanced JavaScript developers alike. We want to help improve the JavaScript ecosystem, by lowering the barrier of entry for newcomers and help seasoned veterans pick up new tricks and remember old ones. In order to achieve this, we have collected hundreds of snippets that can be of use in a wide range of situations. We welcome new contributors and we like fresh ideas, as long as the code is short and easy to grasp in about 30 seconds. The only catch, if you may, is that many of our snippets are not perfectly suited for large, enterprise applications and they might not be deemed production-ready.


In order for 30 seconds of code to be as accessible and useful as possible, all of the snippets in the collection are licensed under the CC0-1.0 License, meaning they are absolutely free to use in any project you like. If you like what we do, you can always credit us, but that is not mandatory.


Today's picks

Our sophisticated robot helpers pick new snippets from our collection daily, so that you can discover new snippets to enhance your projects:

byteSize

Returns the length of a string in bytes.

Convert a given string to a Blob Object and find its size.

const byteSize = str => new Blob([str]).size;
-
byteSize('๐Ÿ˜€'); // 4
-byteSize('Hello World'); // 11
-

createElement

Creates an element from a string (without appending it to the document). If the given string contains multiple elements, only the first one will be returned.

Use document.createElement() to create a new element. Set its innerHTML to the string supplied as the argument. Use ParentNode.firstElementChild to return the element version of the string.

const createElement = str => {
-  const el = document.createElement('div');
-  el.innerHTML = str;
-  return el.firstElementChild;
+30 seconds of code
logo 30 seconds of code
Curated collection of useful JavaScript snippets
that you can understand in 30 seconds or less.
304
snippets
118
contributors
3212
commits
19970
stars
Our philosophy
The core goal of 30 seconds of code is to provide a quality resource for beginner and advanced JavaScript developers alike. We want to help improve the JavaScript ecosystem, by lowering the barrier of entry for newcomers and help seasoned veterans pick up new tricks and remember old ones. In order to achieve this, we have collected hundreds of snippets that can be of use in a wide range of situations. We welcome new contributors and we like fresh ideas, as long as the code is short and easy to grasp in about 30 seconds. The only catch, if you may, is that many of our snippets are not perfectly suited for large, enterprise applications and they might not be deemed production-ready.

In order for 30 seconds of code to be as accessible and useful as possible, all of the snippets in the collection are licensed under the CC0-1.0 License, meaning they are absolutely free to use in any project you like. If you like what we do, you can always credit us, but that is not mandatory.

Today's picks
Our sophisticated robot helpers pick new snippets from our collection daily, so that you can discover new snippets to enhance your projects:
 
delay
Invokes the provided function after wait milliseconds.
Use setTimeout() to delay execution of fn. Use the spread (...) operator to supply the function with an arbitrary number of arguments.
const delay = (fn, wait, ...args) => setTimeout(fn, wait, ...args);
+
delay(
+  function(text) {
+    console.log(text);
+  },
+  1000,
+  'later'
+); // Logs 'later' after one second.
+
prettyBytes
Converts a number in bytes to a human-readable string.
Use an array dictionary of units to be accessed based on the exponent. Use Number.toPrecision() to truncate the number to a certain number of digits. Return the prettified string by building it up, taking into account the supplied options and whether it is negative or not. Omit the second argument, precision, to use a default precision of 3 digits. Omit the third argument, addSpace, to add space between the number and unit by default.
const prettyBytes = (num, precision = 3, addSpace = true) => {
+  const UNITS = ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];
+  if (Math.abs(num) < 1) return num + (addSpace ? ' ' : '') + UNITS[0];
+  const exponent = Math.min(Math.floor(Math.log10(num < 0 ? -num : num) / 3), UNITS.length - 1);
+  const n = Number(((num < 0 ? -num : num) / 1000 ** exponent).toPrecision(precision));
+  return (num < 0 ? '-' : '') + n + (addSpace ? ' ' : '') + UNITS[exponent];
 };
-
const el = createElement(
-  `<div class="container">
-    <p>Hello!</p>
-  </div>`
-);
-console.log(el.className); // 'container'
-
isNil
Returns true if the specified value is null or undefined, false otherwise.
Use the strict equality operator to check if the value and of val are equal to null or undefined.
const isNil = val => val === undefined || val === null;
-
isNil(null); // true
-isNil(undefined); // true
+
prettyBytes(1000); // "1 KB"
+prettyBytes(-27145424323.5821, 5); // "-27.145 GB"
+prettyBytes(123456789, 3, false); // "123MB"
+
sumPower
Returns the sum of the powers of all the numbers from start to end (both inclusive).
Use Array.fill() to create an array of all the numbers in the target range, Array.map() and the exponent operator (**) to raise them to power and Array.reduce() to add them together. Omit the second argument, power, to use a default power of 2. Omit the third argument, start, to use a default starting value of 1.
const sumPower = (end, power = 2, start = 1) =>
+  Array(end + 1 - start)
+    .fill(0)
+    .map((x, i) => (i + start) ** power)
+    .reduce((a, b) => a + b, 0);
+
sumPower(10); // 385
+sumPower(10, 3); //3025
+sumPower(10, 3, 5); //2925
 

Getting started

Related projects
The idea behind 30 seconds of code has inspired some people to create similar collections in other programming languages and environments. Here are the ones we like the most:

Top contributors
chalarangelo Angelos Chalaris
fejes713 Stefan Fejeลก
flxwu Felix Wu
atomiks atomiks
kingdavidmartins King David Martins
kriadmin Rohit Tanwar
iamsoorena Soorena Soleimani
skatcat31 Robert Mennell
How to contribute
Do you have a cool idea for a new snippet? Maybe some code you use often and is not part of our collection? Contributing to 30 seconds of code is as simple as 1,2,3,4!
1
Create
Start by creating a snippet, according to the snippet template. Make sure to follow these simple guidelines:
  • Your snippet title must be unique and the same as the name of the implemented function.
  • Use the snippet description to explain what your snippet does and how it works.
  • Try to keep the snippet's code short and to the point. Use modern techniques and features.
  • Remember to provide an example of how your snippet works.
  • Your snippet should solve a real-world problem, no matter how simple.
  • Never modify README.md or any of the HTML files.
2
Tag
Run npm run tagger from your terminal, then open the tag_database file and tag your snippet appropriately. Multitagging is also supported, just make sure the first tag you specify is on of the major tags and the one that is most relevant to the implemneted function.
3
Test
You can optionally test your snippet to make our job easier. Simply run npm run tester to generate the test files for your snippet. Find the related folder for you snippet under the test directory and write some tests. Remember to run npm run tester again to make sure your tests are passing.
4
Pull request
If you have done everything mentioned above, you should now have an awesome snippet to add to our collection. Simply start a pull request and follow the guidelines provided. Remember to only submit one snippet per pull request, so that we can quickly evaluate and merge your code into the collection.
If you need additional pointers about writing a snippet, be sure to read the complete contribution guidelines.