Use VLOOKUP, one of the lookup and reference functions, when you need to find things in a table or a range by row. For example, look up a price of an automotive part by the part number.

In its simplest form, the VLOOKUP function says:

=VLOOKUP(Value you want to look up, range where you want to lookup the value, the column number in the range containing the return value, Exact Match or Approximate Match – indicated as 0/FALSE or 1/TRUE).

There is something called 'locked reference' in excel which you can use for this, and you use $ symbols to lock a range. For your example, you would use:

=IF(B4<>"",B4/B$1,"")

This locks the 1 in B1 so that when you copy it to rows below, 1 will remain the same.

If you use $B$1, the range will not change when you copy it down a row or across a column.

Une nouvelle conscience planétaire émerge, qui se joue des appartenances et des frontières. Il est temps d’inventer une démocratie pour notre temps, estime Achille Mbembe, historien et philosophe.

This guide is intended to catch you up with the most important reasoning, terms, tools, and approaches to JavaScript testing in 2018.

app.get('/:var(bla|blabla)?', todo)

:var sets the req.param that you don't use. it's only used in this case to set the regex.

(bla|blabla) sets the regex to match, so it matches the strings bla and blablah.

? makes the entire regex optional, so it matches / as well.

This lightweight tool helps you get a sense of your application's schema, as well as any outliers to that schema. Particularly useful when you inherit a codebase with data dump and want to quickly learn how the data's structured. Also useful for finding rare keys.

$ mongo test --eval "var collection = 'users'" variety.js

+------------------------------------------------------------------+
| key                | types              | occurrences | percents |
| ------------------ | ------------       | ----------- | -------- |
| _id                | ObjectId           |           5 |    100.0 |
| name               | String             |           5 |    100.0 |
| bio                | String             |           3 |     60.0 |
| birthday           | Date               |           2 |     40.0 |
| pets               | Array(1),String(1) |           2 |     40.0 |
| someBinData        | BinData-old        |           1 |     20.0 |
| someWeirdLegacyKey | String             |           1 |     20.0 |
+------------------------------------------------------------------+

Infer a probabilistic schema for a MongoDB collection.
Usage

mongodb-schema can be used as a command line tool or programmatically in your application as a node module.

mongodb-schema mongodb://localhost:27017 db.collection

$ mongodump -d some_database -c some_collection
$ mongorestore -d some_other_db -c some_or_other_collection dump/some_collection.bson

db.originalCollectionName.renameCollection('newCollectionName')

You can select the collection via:

mongodump -d some_database -c some_collection

[Optionally, zip the dump (zip some_database.zip some_database/* -r) and scp it elsewhere]

Then restore it:

mongorestore -d some_other_db -c some_or_other_collection dump/some_collection.bson

Existing data in some_or_other_collection will be preserved. That way you can "append" a collection from one database to another.

Prior to version 2.4.3, you will also need to add back your indexes after you copy over your data. Starting with 2.4.3, this process is automatic, and you can disable it with --noIndexRestore.

HTTPie—aitch-tee-tee-pie—is a command line HTTP client with an intuitive UI, JSON support, syntax highlighting, wget-like downloads, plugins, and more.

HTTPie consists of a single http command designed for painless debugging and interaction with HTTP servers, RESTful APIs, and web services:

• Sensible defaults
• Expressive and intuitive command syntax
• Colorized and formatted terminal output
• Built-in JSON support
• Persistent sessions
• Forms and file uploads
• HTTPS, proxies, and authentication support
• Support for arbitrary request data and headers
• Wget-like downloads
• Extensions
• Linux, macOS, and Windows support

Generate massive amounts of fake data in the browser and node.js

Instead of implementing XMLHttpRequest in Node.js to run browser-specific Fetch polyfill, why not go from native http to fetch API directly? Hence node-fetch, minimal code for a window.fetch compatible API on Node.js runtime.

See Matt Andrews' isomorphic-fetch or Leonardo Quixada's cross-fetch for isomorphic usage (exports node-fetch for server-side, whatwg-fetch for client-side).

SuperAgent is light-weight progressive ajax API crafted for flexibility, readability, and a low learning curve after being frustrated with many of the existing request APIs. It also works with Node.js!

Aggregation is a very small JavaScript library for Node.js environments, providing just a single function, for use in ECMAScript 5/6 class inheritance based on mixins. It aggregates a base class and one or more mixin classes into an aggregate class, which then is usually subsequently used as the base class for another class.

mics (pronounce: mix) is a library that makes multiple inheritance in Javascript a breeze. Inspired by the excellent blog post “Real” Mixins with Javascript Classes by Justin Fagnani, mics tries to build a minimal library around the concept of using class expressions (factories) as mixins. mics extends the concepts presented in the blog post by making the mixins first-class citizens that can be directly used to instantiate objects and can be mixed in with other mixins instead of just with classes.