Why TRUE + TRUE = 2: Data Types 

And that's the last in this run of the Basics! Thanks to Dashlane for sponsoring all these: you can get their password manager for free on your first device at www.dashlane.com/tomscott - there's a 30-day free trial, and 10% off with my code, "tomscott".

0:19 the way the text on the screen and Tom's hand raise at the same time is unsettling

PHP: "A language notable for MANY questionable design decisions" I laughed, cried and grimaced so hard at the mention of that absolutely true fact.

"I have been coding for about 30 years" Jesus, in my mind you've been permanently ~25 since 2015. I have to readjust to what Wikipedia claims is your age, but even then, you started super young if that's true...

"Implicit conversions are great" - Famous last words

When “true + true” fades away it doesn’t fully disappear 4:35 Sorry Tom, I’m a big fan of your work

I change the hdmi 1 to hdmi 2 and thats already enough coding for my grandparents

I was taught Fortran at University. They told us to start with "implicit none" and then declare all our variable explicitly Kind of a pain, but it did mean if you accidentally typo'd a variable name it would flag it for you immediately

Thanks for undermining my trust in high-level programming languages. I'm switching to Assembly.

I really like strongly typed languages. If I want to cast it I can do it myself. Otherwise I want to see an error.

Personally, I get really frustrated working with weakly typed languages. Debugging can be hard, but even just understanding what the code is doing can be harder.

4:57 That's why I used the mnemonic "explicitly equals" when writing booleans to remind me to use the second equal. The alliteration and second word reminded me that it was two symbols and not just the one.

I was classically trained in C and then decided to learn JavaScript. A dark time in my life.

Tom is the kind of guy you listen to, even if you worked yourself through that topic countless times before Concerning the topic itself, I prefer explicit declarations, as it makes finding bugs in the program simpler as it forces you to consciously account for these kind of conflicts. I can see why people like to use weak typing, but personally, I rather do not

In python, however, "1.5"*2 is "1.51.5"...

I'll add that you can have implicit declarations within a strongly typed language. Swift does this as an example. So you can make a declaration like var x = "50" You don't need to declare that x is a string, the declaration is implicit. But in usage it'll be strongly typed, so var y = 50 x+y only works if you explicitly cast either of them, like Int(x)+y Recent Java also has implicit local declaration, though not for global variables.

[0:16] Can we just talk about how the green title screen in the background perfectly reacts to Tom's hand gestures? :D

2:46 the type of a variable doesn't get figured out ("inferred") from the code in JS / Python / PHP. Some languages do work like that, but JS just makes a bucket that can fit everything (with quite some overhead) and then just lets you do whatever you want with it. Haskell is a language where it does get inferred from the code using constraint resolution, giving you the (apparent) benefits of not specifying it without that overhead. C#/Java have var, Kotlin has var/val, Scala/Rust have let , C++ has auto, all like Haskell (to various degrees).

Whenever my favorite RU-vidr becomes a school assignment you know I’m choosing the right path

"Weak typing can reduce frustration and just make programmers' lives easier." Weak typing forces you to know exactly what you're doing, and makes screwing up really easy, and the computer probably won't catch it for you. This is the opposite of what you want for beginning programmers.

I love these IT themed videos, they make this noob understand much better what dark magic makes my pc work.

Top five densest things in the universe: Normal Stars Red Dwarfs Neutron Stars Black Holes Node Modules

Also in JS, if you want to evaluate if a value is set to null or not, but one of the valid values IS an empty string, or 0, or etc, that's also where you get problems. It's honestly easier to be more consistent and check for these values explicitly.

Meanwhile in Javascript: 0 == "0" --> true 0 == [ ] --> true "0" == [ ] --> false very intuitive.

Loved what you did with 42 and * there

Having used both weakly and strongly typed languages for years I have to thoroughly disagree with this common "wisdom" that weak/dynamic typing is helpful in any way. The extra overhead for teaching a beginner is, from my real world experience, about half an hour at most. With the advent of broadly type inferred languages, it doesn't save you much typing, either. On the other hand, strong typing gives you a mental framework to work off of which is extremely beneficial to every level of programmer. Not to mention compilers with good error messaging can provide tons of help especially to beginners, based on these strong types. In my opinion, this is an out dated and incorrect notion that has failed to fall out of favor because of entrenchment

5:17 The year is 2050 JavaScript have now "evolved" to the point where a strict comparison is typed like this: _1.5 ============================== "1.5"; // false_ (30 equal signs)

4:03 Body language says “been there, done that”.

Things I learnt from this video: Tom is over 30 years old, or even over 40. He's also been coding for around 30 years. Also some code stuff too idk.

I am about to get my computer science degree and i still watch these videos, they are just fun :)

Everytime I watch one of these Basics videos, I curse my luck because these would have helped me SO MUCH when I began programming 2 years ago and I was trying to wrap my head around stuff like this.

(1:25) Yet people continue to use float/double, and this causes issues in games where the floating point error gives wrong results. Such in one game, where the developer, for some reason, decided that you die when reaching exactly 0 health, and to avoid it going over, it seems to do some check in form of "if damage > health, damage - (damage - health)" or something stupid like that. Rarely, and randomly, your health can suddenly get decimals, and when this happens, you can never die, or almost never. Your health gets closer and closer to 0, but never reaching it. - This would never be an issue if the developer used an int only, and allowed it to be negative. If your health reaches 0 or below, you die.

I work professionally with Javascript, and let me tell you that every time I get to work in a statically typed language it's like heaven. I hope that WASM will be the solution to this hell. Until then, Dart and Typescript it is.

Well said! I grew up with Delphi which was strictly typed, then moved to PHP which is not (although it's getting there as an opt-in feature now), which was my stepping stone to C and C++ which I now work in every day. Still, today when I need to prototype something I throw it together in PHP or Python, and when happy with the idea/design re-write in C. Without the stepping stone of PHP I don't think I would have ever moved to a lower level language and I would not be involved in the FOSS projects that I am today (Looking Glass, Qemu, Linux (kernel), Kodi, etc).

Love these videos, even being an experienced programmer I still find my self learning from these well put together videos

I joined a tech company a couple of years ago not knowing much about computers at all. Your videos really helped me to adapt and understand some things at work and allowed me to excel in my role as an Account Manager there. I'm now taking course on basic networking because of the confidence I have in myself to get it. You have helped install that in me. Thank you so much Tom!

Love how you make sponsor segments interesting.

2:21 "but this is just the Basics..." I see what you did there...

A great example of why some people hate operator overloading with a passion.

As a non coder, that part at the end about password length was especially useful and insightful for me, thanks Tom!

I know this video is a year old, but... "Implicit" anything is the bane of my existence. Implicit interactions may be "easier" to learn provided you know they exist, but that's an extra level of knowledge needed over explicit declarations. You have to remember them while coding and figure them out while reading unfamiliar code, because they aren't defined anywhere. Explicit declarations place - ideally - all of the information you the programmer actually need to know directly into the code, where it can be manually reference if necessary.

01:26 Of course it's 42, that is THE answer after all!

As someone who learned to program in C with a professor that kinda hated weak typing I'm screaming internally at the notion of asking if a string is true, it feels like asking if an apple is a number.

Our comp sci class watched this video in lesson :D. Thanks for creating content like this, it really helps me out learning to program and getting ahead in lessons. keep up the great work :).

3:22 technically, that's probably a type coercion.

The amount of times I've spent a day bugfixing something only to realise I didn't make something static is immeasurable.

i rarely let the ad run, simply skip any sponsorship advertisement or just end the video., but i watch the entire tom's sponsorship ad and its really informative

This a really nice reference for new programmers to learn certain basic stuff including datatypes

The plus sign is the only mathematical operator that gets overloaded for strings, which makes it inconsistent and easy to mess up. That's why some languages use a different character (often the period) for string concatenation, which makes things more consistent and helps avoid these sorts of problems. Unfortunately a lot of programmers don't realize this and complain about the different character being used for concatenation instead of the plus sign. :-\

I'd like to see "====" : Is this the same object in memory ;)

That hand gesture scrolling the screen moment at 0:19 is a thing of beauty.

please continue to do this list , it very helpful and entertaining !

I was expecting "1" + "1" = "b" Edit: Also, I LOL'd at "That's very simple: it's true or false." or null, or open, etc... depending on context. The practical needs of implementation has really done a number on a simple concept.

"I've been coding for about 30 years" Dude, how young did you start?!

Your content and delivery is outstanding. Thank you!

0:19 the way tom hand raises and the text on the background monitor xD

I love the basics I don't even write code I just like being able to somewhat understand it!

Why am I watching Tom explain the stuff I already know and enjoying it? Btw, love your work.

Best Dashlane ad I've seen. The math breakdown was brilliant!

As an absolute novice at programming, I prefer strong typing as it's harder to accidentally screw up 😅

A JavaScript '+' has a third use: integer parsing. Making 1+ + "1" = 2

I was literally calculating that password question yesterday, but i didn't know how many symbols most websites accept. Thank you for answering that!

You made that ad for Dashlane fun to watch, Nice!

I personally prefer Python's average-strength typing - you needn't declare variable types but it'll rarely convert them for you.

"I have been coding for about thirty years and I still absentmindedly screw that up sometimes" Tell me about it. I spent 50% of my coding in a loosely typed language that uses: = for assignment, == for comparison, ~, &, | for logical not, and, or, for i = 1:10 .. . end for loops, 1-based arrays, sub arrays defined as (start : end). The other 50% is in a strongly typed language that uses: := for assignment, = for comparison, NOT, AND, OR for logical not, and, or, for i := 1 to 10 do ... next for loops 0-based arrays sub arrays defined as [start : size] These are not all differences. I screw up all the time, obviously.

Good overview of the basics of data typing, Tom! I've spent the past six years coding in a very old language (Cache Object Script) that was written in the 1960's. It's pre-Unix and pre-"C" so the syntax and typing is completely alien - assigning a variable needs a "SET" and lines don't end in a semicolon like nearly all descendants of "C". What makes it more difficult is that I'm also coding in PHP and JavaScript so there's a lot of swapping syntax back and forth as I go from system to system. Fortunately we're replacing the Content Management System that's based on Cache Script and going to PHP so I get to only program in two languages - it'll be like a mental vacation! The bottom line, though, is that if you learn the fundamentals of programming then for the most part the languages are just the particular dialect you need to get something done. Loops are still loops, Boolean logic is still AND and OR, data storage, string manipulation and more are all conceptually the same, it's just the phrasing used to accomplish the goals that changes. Over the course of my career I've worked in over 30 different languages - from machine code to object oriented languages and the fundamentals are always the same...

I can appreciate this … I used to do horrible things with embedded boolean statements in calculations and then use sign as a branching or formatting conditional

Damn Tom, you're looking *sharp* today ^^

0:49 You completely missed the opportunity to write out “Tom Scott” in binary.

Ive been watching since 2013! still watch your content its still so good keep up the work!

Cool vid, very glad to see Language File and The Basics videos returning

Honestly, Tom Scott is the best at finding weird but amazing facts!

"You will at least have integer" *cries in javascript*

Had a problem just last week where I was sending an alert when a variable equaled true, then a change made somewhere else caused the variable to store 1 and 0 instead of true and false. Well my Alert didn't fire, and I didn't know of a problem for days. The day I learned that "= true" and "!= false" are not the same equation, and the latter is far superior when dealing with important alerts!

4:35 This fade-out was calculated with floating points. 😂

Many moons ago, I started coding using Assembler. I am watching this feeling a bit old (because of the many moons ago), a bit smug (anything you say seems obvious to me), and a bit of a museum piece! :) :) :)

1:25 isn't that 21?

1:19 "In general you will at least have: Integer" JavaScript has left the chat

Definitely looking forward to your basics video on floating points.

Weak typing makes it easy to get buggy code into the really expensive wilderness. Yes, strong typing is a bit of trouble, but you get a lot of "inaccuracies" ironed out immediately, instead of disasters later.

string person = "I "; string subject = "loose programming languages!"; string opinion = "hate "; return person + opinion + subject;

I've finally read a title and understood it before watching the video. A dream come true.

static typing is a superpower. You can have the compiler tell you the errors, and you can fix it in seconds. In languages like JS, you can't, it will just run and possibly give an error or just continue, and you will spend hours tracking it down.

4:42- speaking of bugs that come out later... your true + true is still visible :D

Thank you for never conflating weak typing and dynamic typing, or type inference and dynamic typing.

When you know nothing about coding but find Tom's videos interesting and fun to watch.

Once again love the vid

Those simple times when string variables had to start with $ sign...

"You will at least have integer." *laughs in JavaScript*

This is why I like Typescript a lot. Typescript is (usually) strongly typed, but you can use the shorthand "any" type when you need the language to just get out of the way.

I have been watching your videos for so long, that it turns out that somehow I have not been subscribed. Like what!?! I am now subscribed!

This video is great! I've been teaching Java and C++ for a few years now (I teach primarily college students and middle schoolers) and I always suggest someone new to coding to start with Java. Part of it is my own bias (i learned coding through FRC and FTC) but I believe the strongly typed languages enforce good coding practices.

HAH! As soon as i saw the video title, i knew that Javascript had to be in there.

Great video, you explained topics that can take days in a computer science class.

Great video!! Everything in computing is a “tradeoff” that’s what I love about it!

Sounded like you had had very painful experiences when you talked about the "0" ending up as false

2 + 2 = 5 for very large values of 2

This is great Tom, if always known this in practice, but I'd never had the theory behind my actions. Because of this you can imagine I was big hunting on the reg. With this knowledge under my belt, I trust I'll make better decisions in the future. Cheers!

I love the 42 and * in your examples!

Were you really 5 when you started coding?! Impressive!