flatMap Can Filter AND Transform?!

flatMap is a SECRET WEAPON! Return empty array to REMOVE items, return array with value to KEEP. One pass does filter AND map together! This trick will make your code 10x cleaner!

#javascript #javascripttricks #flatmap #arrayfilter #arraytransformation #javascriptweird #javascriptquiz #codingchallenge #javascriptshorts #javascripttips #functionalprogramming #advancedjavascript

https://www.youtube.com/watch?v=b3SGNML931E

Subquery Returns Multiple Rows In Comparison?!

Using subquery that returns multiple rows in = comparison crashes! SQL doesn't know which row to use. This breaks subqueries! Watch!

#sql #sqltricks #database #sqltutorial #subqueries #multiplerows #sqlquiz #codingchallenge #sqlshorts #sqlbugs #subqueryerrors #sqlwtf

https://www.youtube.com/watch?v=x15LSXR-uVM

Elevator Saga: The elevator programming game (2015)

https://play.elevatorsaga.com/index.html

#HackerNews #ElevatorSaga #ElevatorGame #ProgrammingFun #CodingChallenge #IndieGame

PHP String Increment Magic

Wait for it! PHP can increment strings. See what happens with 'Z'++ and '9'++. This will blow your mind!

#php #phptricks #codingtips #programmingtutorial #phpstringincrement #stringoperations #phpoperators #phpquiz #codingchallenge #phpshorts #phpweird #stringmanipulation

https://www.youtube.com/watch?v=BRIbAfafHSg

Promise.resolve UNWRAPS Thenables?!

Promise.resolve has RECURSIVE unwrapping! Any object with a 'then' method gets called. Nested thenables unwrap ALL the way down until a real value appears. This automatic unwrapping will confuse your async code!

#javascript #javascripttricks #promise.resolve #thenables #asyncunwrapping #javascriptweird #javascriptquiz #codingchallenge #javascriptshorts #javascriptwtf #promisequirks #advancedjavascript

https://www.youtube.com/watch?v=7gDt_tC_Jw8

0.1 + 0.2 In SQL = 0.30000000000000004?!

SQL floating point precision is broken! Adding 0.1 + 0.2 creates a number with precision errors. This breaks financial calculations! Watch!

#sql #sqltricks #database #sqltutorial #floatingpoint #precision #sqlquiz #codingchallenge #sqlshorts #sqlbugs #numericprecision #sqlwtf

https://www.youtube.com/watch?v=C53FQIhge3U

100M-Row Challenge with PHP

https://github.com/tempestphp/100-million-row-challenge

#HackerNews #100MRowChallenge #PHP #TempestPHP #DataPerformance #CodingChallenge

Math.min() > Math.max() Returns TRUE?!

⚠️ YOUR BRAIN WILL EXPLODE! Math.min() is GREATER than Math.max()! This breaks EVERY rule of mathematics! The answer will shock you. 97% of developers get this wrong!

#javascript #javascripttricks #codingchallenge #math.min #math.max #javascriptquiz #javascriptweird #javascriptwtf #mindblown #javascriptbugs #codingtips #javascriptshorts

https://www.youtube.com/watch?v=au8mR2rlVgo

Arrow Functions Have NO arguments?!

Arrow functions BREAK arguments! They don't have the arguments object. This will cause ReferenceError when you try to use it. Regular functions work, arrows don't!

#javascript #javascripttricks #arrowfunctions #argumentsobject #thisbinding #javascriptweird #javascriptquiz #codingchallenge #javascriptshorts #javascriptwtf #functiondifferences #advancedjavascript

https://www.youtube.com/watch?v=rckkbJzGLeE

HAVING Filters After GROUP BY?!

HAVING filters GROUPS, WHERE filters ROWS! HAVING runs after aggregation, WHERE runs before. This order matters and will break your logic!

#sql #sqltricks #having #where #groupby #sqlweird #sqlquiz #codingchallenge #sqlshorts #sqlwtf #aggregation #advancedsql

https://www.youtube.com/watch?v=OMjcmF4mw08