# Introduction

The Nineteenth Byte is CGCC's official chatroom (go check it out!). Its name is a play on the nineteenth hole, and it also refers to golf, which is appropriate for CGCC's chatroom's name. The name is also precisely $$\19\$$ bytes long, as its name states.

# Challenge

Your task is to write a program that outputs Stack Exchange Chat - The Nineteenth Byte exactly. However, if the nineteenth byte and only the nineteenth byte of your source code is removed, it should output only Stack Exchange Chat. Because of this, the best score you can get will be $$\19\$$ bytes. For example, if your code is abcdefghijklmnopqrstuvwxyz, then abcdefghijklmnopqrstuvwxyz must output Stack Exchange Chat - The Nineteenth Byte and abcdefghijklmnopqrtuvwxyz must output Stack Exchange Chat.

# Rules

• Standard loopholes are forbidden.
• Trailing whitespace is allowed.
• Please explain your answer. This is not necessary, but it makes it easier for others to understand.
• Languages newer than the question are allowed. This means you could create your own language where it would be trivial to do this, but don't expect any upvotes.
• You are scored by the length of the program that outputs Stack Exchange Chat - The Nineteenth Byte.
• This is , so shortest code in bytes wins!
• Brownie points for beating my 40 byte 05AB1E anwer. – Makonede Mar 23 at 16:26
• Is this the fastest upvoted challenge in history? 6 upvotes in 17min – ophact Mar 23 at 16:44
• I wish I could learn writing good challenges, for members here – Wasif Mar 23 at 16:45
• @ophact Maybe. :P also, got my 05AB1E solution down to 38 – Makonede Mar 23 at 16:45
• I will give a 100 rep bounty to the first person to find a (non-trivial) 19 byte solution in any language. – Makonede Mar 25 at 22:19

# Jelly, 25 24 bytes

“ÆçƲBnƥẈṛⱮ_ỴȷOṘỵḊĊ»»ḣ19$ Try it online! ## Without the nineteenth byte “ÆçƲBnƥẈṛⱮ_ỴȷOṘỵḊĊ»ḣ19$


Try it online!

It works no matter if you index from 0 or 1!

## Explanation

“ÆçƲBnƥẈṛⱮ_ỴȷOṘỵḊĊ»»ḣ19$Main niladic link “ÆçƲBnƥẈṛⱮ_ỴȷOṘỵḊĊ» "Stack Exchange Chat - The Nineteenth Byte" » [Calculate the byte-wise maximum with]*$   (
ḣ19      Get the first 19 characters
$)  *When indexing from 1, it's actually the first » that is removed, but the result is the same. • explanation please? – Makonede Mar 23 at 16:57 • @Makonede Added – xigoi Mar 23 at 17:10 # Jelly, 25 bytes “¡TƑ9ı2ṆR“¡⁸¢6ṅȯ*ỵ#K»iƇ”h  # Jelly, 25 bytes “¡TƑ9ı2ṆR“¡TḟKY=ɱø~»tƑƇ⁶K  ## How they work “¡TƑ9ı2ṆR“¡⁸¢6ṅȯ*ỵ#K»iƇ”h - Main link. No arguments “¡TƑ9ı2ṆR“¡⁸¢6ṅȯ*ỵ#K» - Pair of compressed strings ["Stack Exchange Chat", " - The Nineteenth Byte"] Ƈ - Keep those for which the following is True: i ”h - They contain "h"; ["Stack Exchange Chat", " - The Nineteenth Byte"] Smash together and output “¡TƑ9ı2ṆR“¡⁸¢6ṅȯ*ỵK»iƇ”h - Main link. No arguments “¡TƑ9ı2ṆR“¡⁸¢6ṅȯ*ỵK» - Pair of compressed strings ["Stack Exchange Chat", "^Backets reamyappenzell"] Ƈ - Keep those for which the following is True: i ”h - They contain "h"; ["Stack Exchange Chat"] Smash together and output  And the second one: “¡TƑ9ı2ṆR“¡TḟKY=ɱø~»tƑƇ⁶K - Main link. No arguments “¡TƑ9ı2ṆR“¡TḟKY=ɱø~» - Pair of compressed strings ["Stack Exchange Chat", "- The Nineteenth Byte"] ƑƇ - Keep those where the following has no effect: t ⁶ - Removing spaces from the front and end; ["Stack Exchange Chat", "- The Nineteenth Byte"] K - Join with spaces; "Stack Exchange Chat - The Nineteenth Byte" “¡TƑ9ı2ṆR“¡TḟKY=ɱø»tƑƇ⁶K - Main link. No arguments “¡TƑ9ı2ṆR“¡TḟKY=ɱø» - Pair of compressed strings ["Stack Exchange Chat", " Backets reamyappenzell"] ƑƇ - Keep those where the following has no effect: t ⁶ - Removing spaces from the front and end; ["Stack Exchange Chat"] K - Join with spaces; "Stack Exchange Chat"  • Welp, time to go change my name to Backets reamyappenzell – pxeger Mar 23 at 17:37 • @pxeger inspired by his "many users of ppcg answer – ophact Mar 23 at 18:02 • How does # turn ^Backets reamyappenzell into  - The Nineteenth Byte? – Jonah Mar 23 at 18:17 • @Jonah The # is part of a compressed string (delimited with “...». Compressed strings work by treating their contents as a base-250 number, with each digit being a character in Jelly's code page, then repeatedly breaking up that number to generating words and characters. Adding or removing the # changes this base-250 number (same way that 12345 and 1245 are different numbers in base 10), and so would decompress to a different string – caird coinheringaahing Mar 23 at 18:23 • @pxeger Careful, I learnt the hard way that name changes stick with you for far longer than you thought... – caird coinheringaahing Mar 23 at 20:38 # JavaScript (V8), 66 bytes The nineteenth byte is the X. print("Stack",(s="X"&&" - The Nineteenth Byte","Exchange Chat"+s))  Try it online! Try it online! (nineteenth byte removed) ### Commented print( // print: "Stack", // the first word followed by an implicit space ( // s = "X" && // define s as either " - The Nineteenth Byte" " - The Nineteenth Byte", // or an empty string if the 'X' is removed "Exchange Chat" + s // append "Exchange Chat" followed by s ) // ) // end  • this was my original strategy (no mistakes) but then I decided to golf it more (failed) +1 – ophact Mar 23 at 17:25 • @Wasif apparent error that went unnoticed when I was creating my solution – ophact Mar 23 at 17:26 • @ophact Oh, I see. Variables that are defined only on some code paths are sometimes misleading. :-/ – Arnauld Mar 23 at 17:31 • yeah, got +3 votes for some reason. At least I got the Disciplined badge... – ophact Mar 23 at 17:32 # Zsh, 54 bytes set Exchange Chat \ - The Nineteenth Byte <<<Stack\$@


Try it online!

set assigns the given words to the default variable $@. As with the previous one, \ joins the two lines into one call to set, instead of treating - The Nineteenth Byte as a command (which does nothing). ## Zsh, 55 bytes 1=" Exchange Chat"\ " - The Nineteenth Byte" <<<Stack$1


Try it online!

Idea boringly copied from @xnor's genius answer. The \ escapes the newline, which concatenates the two strings; without it, the second line is ignored as an undefined command.

## Zsh, 58 bytes

1=Stack\ Exchang
2=" - The Nineteenth Byte"
<<<$1e\ Chat$2


Try it online!

The 19th byte is the second =, which changes that line from a variable assignment to an undefined command which does nothing. Then, when printing, $2 defaults to empty. # Python 2, 66 bytes s,y='Stack Exch',01 print s+'ange Chat'+' - The Nineteenth Byte'*y  Try it online! Not really a smart answer. :p The nineteenth byte here is the 1. y is 0 or 1 depending on if the nineteenth byte is removed. thanks to pxeger for -2 bytes • 66 (idea stolen from @ophact's JS answer): Try it online! – pxeger Mar 23 at 17:05 • @pxeger good catch but sadly Neil pointed out a mistake in my answer which forced me to delete it. The octal number was probably the only takeaway from the answer – ophact Mar 23 at 17:20 • @pxeger cool. Actually I had tried the same trick in Python 3, but y=01 gives syntax error there. Not sure why the behaviour is like that. – Manish Kundu Mar 23 at 17:20 • @ManishKundu 01 is octal, but that's not obvious to look at unless you're familiar with C already, so it was removed in favour of an 0o prefix in Python 3 – pxeger Mar 23 at 17:22 # C (gcc), 69 bytes Without the removal of the 19th byte, the full string (which is much less than 119 characters) is printed; if the 19th byte is removed, only 19 characters are printed instead. main(){printf("%.119s","Stack Exchange Chat - The Nineteenth Byte");}  Try it online! With the 19th byte removed: Try it online! # Emotion, 34 bytes 😇😘🧖🚵🧖💫😋🧖💙🤙💁🤹☝🍓🧖💖🍸😚🤕😔😘😉💚🙌🙎🥥🤤👨🤑💇👱💔😯😨  The nineteenth byte is 🤕. Try it online! • Is this language made for golfing? Also, is there a tutorial I can learn from? – Razetime Mar 24 at 16:41 • @Razetime It's a language I made for golfing a couple of years ago, except it's not very efficient. Currently, I am rewriting the entire language with a different type system and may make a tutorial on the new version. – Quantum64 Mar 25 at 9:02 # Scala 3, 90 bytes val x="Stack Ex"+a/*/ */+" - The Nineteenth Byte" def a="change Chat" @main def m=print(x)  Try it in Scastie! With the nineteenth byte removed: val x="Stack Ex"+a// */+" - The Nineteenth Byte" def a="change Chat" @main def m=print(x)  Try it in Scastie! The syntax highlighting should show what happens. This would be a byte shorter in a language without nested comments, since the space in /*/ */ wouldn't be needed, but I just like Scala :P A possible solution with a newline that doesn't work because of parsing rules: val x="Stack E"+a// +" - The Nineteenth Byte" def a="xchange Chat" @main def m=print(x)  • first answer to make use of comments, +1 – ophact Mar 23 at 16:50 • Hi, until what reputation you'll award the bounties on good old question answers? – Wasif Mar 24 at 13:15 • @Wasif I'll award them as long as I don't go below 5000 when I award one, so feel free to answer some old questions! (btw if you have any more questions, could you please ask in chat or on comments to the actual post?) – user Mar 24 at 13:34 # Python 3.8 (pre-release), 72 bytes print('Stack Exch{1}'.format(x:='ange Chat',x+' - The Nineteenth Byte'))  Try it online! Different approach than @ManishKundu solution Nineteenth byte is 1 removing it will result 0 to only suffix hange Chat Thanks to @ZaelinGoodman for insight -6 bytes to @Makonede • -5 with the walrus operator :=. – Makonede Mar 23 at 17:47 • -1 more (for a total of -6) making use of implicit str.format arguments: 'a{}b{}c'.format('1','2') -> 'a1b2c' – Makonede Mar 23 at 17:51 • Also, it's better to be consistent with quotes. EDIT: corrected a capitalization error in your code. – Makonede Mar 23 at 18:32 • @Makonede thanks – Wasif Mar 24 at 6:36 • Please fix the capitalization error in your code as well. And it's recommended (but not necessary) to stick to a single type of quotation marks the whole program. – Makonede Mar 24 at 16:39 # Python 2, 65 bytes b='Stack Excha' n=88 print b+'nge Chat - The Nineteenth Byte'[:n]  Works in Python 3 trivially for 66 bytes # Scratch 3.0, 10 blocks/160 bytes define set[outpuuut v]to[Stack Exchange Chat - The Nineteenth Byte set[outpuuu v]to[Stack Exchange Chat if<(outpuuut)>(0)>then say(outpuuut else say(outpuuu end  This outputs Stack Exchange Chat - The Nineteenth Byte Because Scratch is a block-based language, it may not seem obvious on how to remove a byte at first. But thankfully, there exists a text format called ScratchBlocks which we seem to allow for scoring. The above ScratchBlocks corresponds to the following real blocks: Try it on Scratch! Removing the 19th byte of this program gives define set[outpuuu v]to[Stack Exchange Chat - The Nineteenth Byte set[outpuuu v]to[Stack Exchange Chat if<(outpuuut)>(0)>then say(outpuuut else say(outpuuu end  This outputs Stack Exchange Chat Try it on Scratch! Explanation coming soon • Could the variable names be shortened by lengthening the function name? – ophact Mar 24 at 19:17 • @ophact They can actually! This saves 23 bytes. – Makonede Mar 25 at 16:51 # ><>, 62 bytes "Stack Exch"\" - "< " tahC egna"/r>o<r/ eeteniN ehT"\"etyB htn  Try it online! Try it without the Nineteenth byte I've been playing around with ><> this week and this one was kind of a freebie, although it still turned out to be an interesting packing problem that ended up getting quite lucky at the end. The Nineteenth byte is unsurprisingly the < at the end of the first row. With or without it, we'll execute "Stack Exchange Chat ", pushing that string onto the stack (in reverse order; usually we want to push strings backwards but here it's convenient to start with the prefix so we'll just reverse the stack later instead). At this point, the program encounters the / at the end of the second row, hitting it from the right and heading down, conveniently going through the space between "Nineteenth" and "Byte", then wrapping around vertically and either heading leftwards on the first or second row. With the <, we execute "The Nineteenth Byte", pushing that string on the stack and then head to the output gadget, and without it we head directly to the output. The output is done by first reversing the stack with r, and then heading into the bottomless pit of >o< which executes the output instruction o endlessly until the stack is emptied and the program exits via error. # Python 2, 58 bytes s="Exchange Chat "\ "- The Nineteenth Byte" print"Stack",s  The 19th byte is the \ at the end of the first line. It acts as a line continuation character to make the full line be "Exchange Chat ""- The Nineteenth Byte" using Python's automatic concatenation of adjacent string literals. Without the \, the line ends there, and the second line is lonely string value that doesn't do anything. The truncated string ends in a space, which is fine because the challenge allows for trailing whitespace. Python 2, 61 bytes s="Exchange Chat"+--1*" - The Nineteenth Byte" print"Stack",s  The 19th byte is a -. Originally we append --1 (so, 1) copies of the string " - The Nineteenth Byte", with the 19th byte is removed, this is -1 copies which is nothing. # Husk, 25 23 bytes ΣüL½¨ḟKȦΞ×ėCȧt-ξḟ%Nhβ/y  Try it online! Try it online without the 19th byte! ### Explanation ¨ḟKȦΞ×ėCȧt-ξḟ%Nhβ/y is a compressed string, equivalent to "Stack Exchange Chat - The Nineteenth Byte". If we remove N (the nineteenth byte of the program) we get ¨ḟKȦΞ×ėCȧt-ξḟ%hβ/y, which is equivalent to "Stack Exchange Chat - Thefischer\n Byte" (\n being a newline character). Now, starting from one of these two strings:  "Stack Exchange Chat - The Nineteenth Byte" "Stack Exchange Chat - Thefischer\n Byte" ½ Split the string in half ["Stack Exchange Chat -", ["Stack Exchange Chat", " The Nineteenth Byte"] " - Thefischer\n Byte"] üL nub by length: remove strings with the same length as previous ones ["Stack Exchange Chat -", ["Stack Exchange Chat"] " The Nineteenth Byte"] Σ Join the strings together "Stack Exchange Chat - The Nineteenth Byte" "Stack Exchange Chat"  # Factor, 95 94 87 bytes Saved 1 precious byte thanks to @OriginalOriginalOriginalVI! Saved 7 more bytes thanks to @Bubbler! "Stack Exchange C"f " - The Nineteenth Byte""hat"rot [ prepend nip ] [ glue ] if* print  Try it online! Explained: "Stack Exchange C"f " - The Nineteenth Byte""hat" ! push items on the stack, ! f (false) value is 19th char rot ! rotate, f now at top of stack ! if f is missing, "Stack Exchange C" ! is at the top [ prepend nip ] [ glue] if* print ! if* f is found, glue the strings and print. ! if* a string is found, it is considered to ! be true, retain it on the stack, swap & glue ! the top strings, drop the "19th Byte" string, ! append and print.  Old version: "Stack Exchange C"f "hat"" - The Nineteenth Byte"rot [ nip swap append ] [ 3append ] if* print  Try it online! Explained: "Stack Exchange C"f "hat"" - The Nineteenth Byte" ! push items on the stack, ! f (false) value is 19th char rot ! rotate, f now at top of stack ! if f is missing, "Stack Exchange C" ! is at the top [ nip swap append ] [ 3append ] if* print ! if* f is found, append the strings and print. ! if* a string is found, it is considered to ! be true, retain it on the stack, drop the ! "19th Byte" string, swap stack strings, ! append and print.  • @Makonede No, it doesn't. Looks like those are all standard. – user Mar 23 at 21:36 • By the way, you can remove the space before rot. – user Mar 23 at 21:38 • @OriginalOriginalOriginalVI oops I missed it! thanks! – hdrz Mar 23 at 21:39 • glue is a shorter word to join three strings. Though it has different argument order, it doesn't matter much here. Also, prepend is shorter than swap append. 87 bytes. – Bubbler Mar 24 at 0:39 • @Bubbler I missed those two words in the manual somehow.. Thanks for that. – hdrz Mar 24 at 7:06 # PowerShell 7, 60 bytes 'Stack Exchange'+(!0 ?' Chat - The Nineteenth Byte':' Chat') # ^ # 19th byte  No TIO because the ternary operator is not supported in powershell 6 and below ## Alternate Solutions ### PowerShell 7, 60 bytes "Stack Exchan$($x=!0 ?' - The Nineteenth Byte':'')ge Chat$x"
#                 ^
#                 19th byte


### PowerShell, 61 58 bytes

-3 bytes thanks to @mazzy!!

"Stack Exchange {01}"-f'Chat','Chat - The Nineteenth Byte'
#                 ^
#                 19th byte


Try it online!

• – mazzy Mar 24 at 3:58
• @mazzy I had a feeling you'd come along and find a smarter way to do one of my secondary solutions lol. Thanks! – Zaelin Goodman Mar 24 at 11:55
• fair competition of alternatives :) – mazzy Mar 24 at 12:01

# SNOBOL4 (CSNOBOL4), 90 bytes

              Y =1
X =GT(Y) ' - The Nineteenth Byte'
OUTPUT ='Stack Exchange Chat' X
END


Try it online!

The nineteenth byte here is the 1. SNOBOL treats an empty string as 0, and an empty right-hand assignment as an empty string. So when the byte is removed, the program assigns a value of 0 to Y, and the comparison Y GT (implicit 0) fails, hence X is assigned an empty value as well.

# Java, 10483 72 bytes

$->"Stack ExchangeA Chat".replaceAll("A(.*)","$1 - The Nineteenth Byte")


The nineteenth byte is A.

Saved 21 bytes thanks to 79037662.

Saved 11 bytes thanks to Olivier Grégoire.

Try it online!

Try it online (without the nineteenth byte)!

• Replace ==18 with <19, and ("Ec","Exc") with ("E","Ex") to easily save a few bytes. – 79037662 Mar 23 at 19:19
• Save some bytes by not using length and replace, which are long function names. Here the first 1 is the 19th byte: tio.run/##PY5Pa8MwDMXv/… – 79037662 Mar 23 at 19:25
• @79037662 Great idea! Thanks. – iota Mar 23 at 20:22
• 72 bytes – Olivier Grégoire Mar 24 at 10:07
• @OlivierGrégoire Good one. – iota Mar 24 at 13:00

# R, 7268 63 bytes

-4 bytes thanks to Dominic van Essen.

cat(scan(,"",3+0004))
Stack Exchange Chat - The Nineteenth Byte


Try it online!

The 19th byte is the 4. In the unaltered version, scan will read 7 words from the next line, and then print them. If you remove the 4, scan will read only 3 words and then print them.

• 68 bytes... – Dominic van Essen Mar 25 at 12:29
• @DominicvanEssen Nice, thanks! I had tried if(10)y=... but that led to an error when y is not defined; setting to NULL with your solution is elegant. – Robin Ryder Mar 25 at 12:35
• This is also 68 bytes, and seems really wasteful with all the whitespace, but I don't know if it can be golfed any more... – Dominic van Essen Mar 25 at 12:46

# Excel, 73 70 bytes

Updated thanks to @EngineeringToast

=LET(a,"Stack ",b,1,a&"Exchange Chat"&IF(b," - The Nineteenth Byte",))


Original

=LET(s,"Sta",n,30--11,LEFT(s&"ck Exchange Chat - The Nineteenth Byte",n))


Shows all characters as is; the left 19 characters if the 19th byte (-) is deleted.

• 71 bytes: =LET(a,"Stack ",b,10,a&"Exchange Chat"&IF(b," - The Nineteenth Byte",)) where the 19th bytes is the 1 inside b,10. – Engineer Toast Mar 25 at 17:20
• Thanks @EngineerToast. We can get it down to 70 eliminating the 0. – Axuary Mar 25 at 17:45

# Wolfram Language (Mathematica), 60 bytes

"Stack Exc"~Print~##&["hange Chat"," - The Nineteenth Byte"]


Try it online!

The 19th byte is one of the #s. ## represents a sequence of all arguments, but # represents only the first argument.

# APL (Dyalog Classic), 61 bytes

¯12⌽∊('ge Chat'{⍺ ⍵}' - The Nineteenth Byte'),'Stack Exchan'


¯12⌽∊  ⍝ Rotate right 12
{⍺ ⍵}  ⍝ Concatenate
,      ⍝ Concatenate


Try it online!

• Welcome to Code Golf! I think you left a newline at the end, but you can also do this for 53 bytes. – user Mar 23 at 18:53
• @Makonede Right, but I thought it would be appropriate to welcome them to CGCC, since they're a new contributor. – user Mar 23 at 19:42
• @OriginalOriginalOriginalVI Dang it, I knew there should be a way to use left tack. The selfie seems so obvious now, good call. – Andrew Ogden Mar 23 at 19:48
• @OriginalOriginalOriginalVI I am new, but I've answered one other :) codegolf.stackexchange.com/a/220985/92642 – Andrew Ogden Mar 23 at 19:50
• @OriginalOriginalOriginalVI Thanks! I'm glad I discovered code golf, it makes learning a new language less tedious :) – Andrew Ogden Mar 23 at 19:59

# Retina 0.8.2, 51 bytes


Stack Exchange Chat - The Nineteenth Byte
ht.*
hat


Try it online! Explanation: Tries to insert the whole string, but if the 19th byte (the a) is deleted, then replaces everything after the C with hat.

# 05AB1E, 27 bytes

” -€€¥ŠteenthÄÁ” õs”Â‚‹ºŠÆÿ

” -€€¥ŠteenthÄÁ” # Compressed string " - The Nineteenth Byte"
õ               # push the empty string
(s)             # (swap back to the other string)
”Â‚‹ºŠÆÿ      # push compressed string "Stack Exchange Chatÿ"
# where ÿ is replaced by the string on the top of the stack

• s can also be ‎\‎ or Š. – Makonede Mar 23 at 21:53

# shortC, 54 bytes

Ds"Exchange Chat\x20- The Nineteenth Byte"
AJ"Stack "s


Try it online!

### Without the Nineteenth byte

Ds"Exchange Chat\x0- The Nineteenth Byte"
AJ"Stack "s


Try it online!

\x20 denotes a space character, removing the 2 we get \x0 (null character) which in C is the string terminator.

# Pxem, filename: 2 bytes + content: 64 bytes = 66 bytes.

Thank you for commenting me that I need to use content of the file.

## Filename

.e


## Content

Stack Exchange Cha.p.c.c.zt - The Nineteenth Byte.p.d.a.v.st.v.p


## How it works

• Every command substring consists of a dot and a char.
• Every non-command substring is considered to be a command to push each of the string from backwards.
• I.e. literals.
• Filename is main routine; content is subroutine.
• .e calls subroutine.
• 19th byte on content is . of .p --- a command to pop each to putchar().
• Then the stack would be empty.
• .c is dup() iff not empty; nop() otherwise.
• .z ... .a is while size<2 || pop!=pop; do ... ;done.
• .d is exit() on filename; return on content.
• .v reverses entire stack.

• Sorry, but this is invalid as the code does not contain anything. The rules specifically state "the nineteenth byte of your source code," not "the nineteenth byte of your filename." – Makonede Mar 24 at 16:40
• So, isn't filename a source code, although filename is main routine for Pxem? – tail spark rabbit ear Mar 25 at 1:11
• Even though programs are stored in the filename, that doesn't make the filename the source code. Also, please delete your answer instead of marking it as disqualified. – Makonede Mar 25 at 1:32
• Yep, that works! – Makonede Mar 25 at 1:51

# Python 2, 65 bytes

a="Exchange Chat"
"#";a+=" - The Nineteenth Byte"
print"Stack",a


The nineteenth byte is the quotation mark before the hashtag. Removing it turns line 2 into a comment.

Works in Python 3 for 67 bytes, by adding brackets for the print() function.

• Welcome to code golf! Nice idea and competitive as well! – movatica Mar 24 at 16:27
• Good first answer indeed! You can save a byte by removing the space between print and "Stack": Try it online! – Makonede Mar 25 at 1:34
• @Makonede Thanks for your help. I have updated the answer. – user101772 Mar 25 at 6:25
• "Hashtag" ..... – ophact Apr 11 at 11:36

# Japt, 36 bytes

The nineteenth byte is the i, if it's removed the two strings are essentially separated by the comma operator instead. The first compressed string is manually unrolled a bit to control the position of the i command to be the nineteenth byte.

 - T” Ná2çh By’iStack ExÖˆge C•t
- T” Ná2çh By’                   // Compressed string " - The Nineteenth Byte", slightly manually decompressed to control the position of the next command.
i                  // This is the nineteenth byte, prepend to the above string, if removed, effectively becomes the comma operator instead.
Stack ExÖˆge C•t // Compressed string "Stack Exchange Chat"


Try it here.

# Python, 73 bytes

x,t="hange Chat"," ";print("Stack Exc"+x,bool(t)*"- The Nineteenth Byte")


Sure it could be golfed a bit more... first looking for an alternative to bool

# Husk, 31 bytes

↓0000+¨ḟKȦΞ×ėCȦt¨↑30¨ -ξḞẊNτβ/y


Try it online!

↓0000                           Drop 0 (does nothing)
+                          Concatenate these strings:
¨ḟKȦΞ×ėCȦt¨               Compressed "Stack Exchange Chat"
↑30            Take 30 characters from...
¨ -ξḞẊNτβ/y Compressed " - The Nineteenth Byte"


The 3 is the 19th byte, so removing it makes ↑0¨ -ξḞẊNτβ/y which is the empty string.