Loading... Forever

Question

Your challenge is to make an infinite loading screen, that looks like this:

enter image description here

---

Or, to be more specific:

• Take no input.
• Output Loading..., with a trailing space, but no trailing newline.
• Infinitely cycle through the chars |, /, - and \: every 0.25 seconds, overwrite the last one with the next in the sequence. You can overwrite just the last character, or delete and rewrite the whole line, as long Loading... remains unchanged.

---

Rules

• The output text must look exactly as specified. Trailing newlines/spaces are acceptable.
• You should not wait 0.25 seconds before initially showing output - the first frame should be printed as soon as the program is run.
• Your program should be able to run indefinitely. For example, if you use a counter for frames, the counter should never cause an error by exceeding the maximum in your language.
• Although the waiting period between each "frame" should be 0.25 seconds, obviously this will never be exact - an error margin of 10% or so is allowed.
• You may submit a function, but it must print to stdout.
• You can submit an answer in a non-console (but still text-based) environment, as long as it is capable of producing the loading animation.
• This is code-golf, so the shortest solution (in bytes) wins. Standard code-golf loopholes apply.
• If possible, please provide a gif of your loading screen in action.

---

Example

Here is the C++ code I used to create the example (ungolfed):

#include <iostream>
#include <string>
#include <thread>
using namespace std;
int main() {
 string cycle = "|/-\\";
 int i = 0;
 cout << "Loading... ";
 while (true) {
 // Print current character
 cout << cycle[i];
 // Sleep for 0.25 seconds
 this_thread::sleep_for(chrono::milliseconds(250));
 // Delete last character, then increase counter.
 cout << "\b";
 i = ++i % 4;
 }
}

May the best golfer win!

• ETHproductions: Can submissions wait 0.25 seconds before initially displaying output?
• FlipTack: No, but thanks for mentioning that, I'll add it to the rules @ETHproductions
• Copper: Is a trailing newline (after the animating symbol) acceptable?
• FlipTack: Of course :) @Copper
• FlipTack: @TheBitByte it means that, theoretically, nothing inside your program will cause it to error - such as a counter overflowing or reaching maximum recursion depth.

Answer 1

Java 7, (削除) 121 (削除ここまで) 118 bytes

void f()throws Exception{for(int k=0;;k++){System.out.print("\rLoading... 
"+"|/-\\".charAt(k%=4));Thread.sleep(250);}}

Gif animation:

enter image description here

Answer 2

C function, 73 bytes

i;f(){for(;write(1,"\rLoading... -\b\\\b|\b/",13+i%8);i++)usleep(1<<17);}

Tested on SystemResque-Cd 4.9.6 in this program:

#include <stdio.h>
#include <unistd.h>
/*
i;
f(){
 for(
 ;
 write(1, "\rLoading... -\b\\\b|\b/", 13+i%8);
 i++
 ){
 usleep(1<<17);
 }
}
*/
i;f(){for(;write(1,"\rLoading... -\b\\\b|\b/",13+i%8);i++)usleep(1<<17);}
int main(){
 f();
 return 0;
}

compiled with gcc 4.9.4

• DJMcMayhem: Welcome to the site!

Answer 3

Japt, 38 bytes

@Oq Oo`LoÃHg... `+"|/-\\"gW°%4)1
a#úiU

Try it online!

How it works

@Oq Oo`LoÃHg... `+"|/-\\"gW°%4)1
a#úiU
@ Declare a function...
 Oq that clears the screen,
 Oo"Loading... " prints this string,
 +"|/-\\"gW++%4 plus the spinner char (using a variable W),
 )1 and finally returns 1
 and implicitly store this function to U.
a Call U once (return 1 is needed for this)
 #úiU and call U every 250 milliseconds.

By the nature of Japt syntax, it's impossible to call U() directly (well, it's possible using JS directive $...$ but it's too long after all.) So we use U.a() method that calls U with numbers from 0 to infinity until U returns true. If you omit )1 at the end of the first line and try running it, your browser will hang.

Without the initial U() call, the output window will show the implicit output (seemingly random integer value) before first showing the Loading... text.

Finally, a#úiU actually translates to U.a(250 .i(U)), which registers the 250ms loop first and then passes the return value (which happens to be undefined) to U.a (which accepts optional function argument, but seems to do nothing special with undefined).

• Shaggy: 32 bytes

Answer 4

Julia, 61 bytes

while [email protected]("\rLoading... "*["|/-\\"...])==sleep(1/4)end

(Don't) try it online!

gif demo

Answer 5

Zsh, 56 bytes

while for i (\| / - \\)printf \\rLoading...$i&&sleep .25

Attempt This Online!

Answer 6

Bespoke, 535 bytes

PUT XX:DIGITNINE BI
PUT XX:FOUR FIFTH
PUT XX:FOUR SEVENTH
PUT XXX:I BI FOUR
PUSH I H V
PUT XX:TRI BI
PUT XX:FOUR SEXTET
DO COPY
DO COPY
PUT XXX:I NUMBERZERO TRI
PUT XXX:I I NUMBERZERO
PUT XXX:I NUMBERZERO FIFTH
PUT XXX:I NUMBERZERO NUMBERZERO
PUT XX:DIGITNINE SEVENTH
PUT XXX:I I I
PUT XX:SEVENTH SEXTET
PUSH I
CONTROL WHILE
OUTPUT CH
DO COPY
CONTROL END
CONTROL DOWHILE
DO COPY
PUT XXXX:FIFTH I I I;STACKTOP QUOTIENTOF
PUSH FOUR STACKTOP MODULO
PUSH BI STACKTOP PLUS
DO COPYN
OUTPUT CH
PUSH INTEIGHT;OUTPUT CH
STACKTOP PLUSONE
DO COPY

A loading animation in a terminal, with the text "Loading... " and a clockwise-spinning line.

Note: at the speed that the Python-based Bespoke interpreter runs on my computer, a time interval close enough to 0.25 seconds happens every 5111 iterations of my program's main loop. Bespoke has no command for waiting a specific length of time.

(Also, the arithmetic I do on my counter will theoretically take longer and longer to do as it gets higher, because of the way ints work in Python. I can rewrite my program if this is an issue.)

Answer 7

Bash, 62 bytes

c='|/-\';for((;;)){ echo Loading... ${c:d++%4:1}^[M;sleep .25;}

where ^[ represents ESC (ASCII 0x1b), which typically you can get by pressing CtrlV and then ESC.

ESC M is RI, reverse linefeed.

If you don't care about running indefinitely, you can save 2 bytes by using a recursive function:

c='|/-\';f(){ echo Loading... ${c:d++%4:1}^[M;sleep .25;f;};f

Answer 8

JavaScript (ES6), 90 bytes

(F=(i=0)=>{(c=console).clear();c.log('loading... '+'|/-\\'[i]);setTimeout(F,250,-~i%4)})()

• ETHproductions: i will eventually overflow, since it just keeps going up without modulation. This can be fixed at no cost with c.log('loading... '+'|/-\\'[i]);setTimeout(F,250,-~i%4)
• George Reith: @ETHproductions Good catch, the poor user would only have to wait a mere 71 billion years.

Answer 9

Node, 72 bytes (70 with literal)

c=0;setInterval(_=>console.log('\x1BcLoading... '+'/-\\|'[c=-~c%4]),250)

If you replace \x1B with the literal escape character you can cut another 2 bytes. You don't need to call anything.

• Adalynn: Would setInterval(_=>console.log('\x1BcLoading... '+'/-\\|'[c=-~c%4]),c=250) work since c is being mod-ed by four every time?

Answer 10

Swift 3, 75 bytes

do{"|/-\\".characters.map{print("\u{001B}[2J\nLoading... \(0ドル)");sleep(1)}}

I need to use \u{001B} (ESCAPE) and [2J (clear screen) here because the old system API is deprecated in Swift 3 and I can't use \r on Mac/Linux. I would lose bytes if I had to use the length posix_spawn call or NSTask. I also hate having to access a string's CharacterView in order to map over each character. At least I saved some bytes by using do instead of a while loop.

Answer 11

Python 3, (削除) 86 (削除ここまで) 83 bytes

GIF to follow. Golfing suggestions welcome as this is still a little verbose. -3 bytes thanks to Flp.Tkc.

import time
i=1
while i:print(end="\rLoading... "+"/-\|"[i%4]);time.sleep(.25);i+=1

• FlipTack: You can stick the \r before the Loading to save the costly bytes for end=. Note that this solution is extremely similar
• Sherlock9: @Flp.Tkc I could have sworn that there were no other Python answers on here. Thanks for the heads up. Also, that tip doesn't work as Python 3's print has the default end of \n which screws up the updating. Thanks anyway.
• FlipTack: In that case you could do print(end="\rLoading... "+"/-\|"[i%4])

Answer 12

F# (interactive), 81 bytes

async{while 1>0 do for c in"|/-\\"do printf"\rLoading... %O"c;do!Async.Sleep 250}

In order to run it in F# interactive, you have to pass it to Async.Start or Async.RunSynchronously.

For reference, a little longer non-async version:

while 1>0 do for c in"|/-\\"do printf"\rLoading... %O"c;System.Threading.Thread.Sleep 250

and a slightly outdated gif :)

enter image description here

• FlipTack: Welcome to PPCG. Nice answer :)

Answer 13

SmileBASIC, 57 bytes

@L CLS?"Loading... "+"|/-\"[I]:I=(I+1)MOD 4 WAIT 15 GOTO@L

Ungolfed:

@L 'loop start
CLS 'clear console
?"Loading... "+"|/-\"[I] 'construct our output and print
I=(I+1)MOD 4 'inc counter, MOD to prevent overflow
GOTO @L 'loop

Answer 14

SmileBASIC, (削除) 51 (削除ここまで) 46 bytes

CLS?"Loading... ";"|\-/"[3AND MAINCNT/15]EXEC.

Answer 15

PKod , 48 bytes ~ Non-Competing

Possibly the only way I can do this, as PKod only has one write-able variable lL=oo=ao=do=io=no=go=.ooo =|oyw=/oyw=-oyw=\oywl<

Explanation: l - Clear screen and since its the first char, allow printing no operation (NOP) chars
 L - NOP, thus print "L"
 =oo=ao=do=io=no=go=.ooo - Set as certain chars and print them.
 (space) - Another NOP, thus print a space
 =|oyw - Set char as "|", print it, then wait a quarter of a second and remove it
 =/oyw=-oyw=\oywl - Same as above, with different symbols to match the challenge
 < - Go back to the start

"Gif" (more like mp4): https://i.gyazo.com/577dd164313a6b2e5dbf40249efb435d.mp4

You can see quote marks around the code in the console, thats because cmd tries to do stuff with my "<" and would return an error. It's just to nicely pass the code to the interpeter without cmd interfering.

• The Fifth Marshal: Why is this non-competing?

Answer 16

Bash, 100 bytes

while [ 1 ]; do for i in `echo '|/-\' | grep -o .`; do printf $'\rLoading...'$i;sleep 0.25;done;done

This is not nicely golfed, so please tell me where I can improve here.

---

This does work, and has been tested on a Raspbian Raspberry Pi, an Amazon server, and an Ubuntu machine. This would not work on a Solaris machine because the sleep command on those systems cannot take inputs less than 1.

Answer 17

C#, (削除) 183 (削除ここまで) (削除) 180 (削除ここまで) (削除) 178 (削除ここまで) (削除) 170 (削除ここまで) (削除) 161 (削除ここまで) 140 bytes

I know a C# solution has already been posted, but this one is a fully functional console program (including usings) in less bytes!

Golfed

class P{static void Main(){for(int i=0;;){System.Console.Write("\rLoading... "+@"|/-\"[i=i++==3?0:i]);System.Threading.Thread.Sleep(250);}}}

Ungolfed

class P
{
 static void Main()
 {
 for (int i = 0; ;)
 {
 System.Console.Write("Loading... "+@"|/-\"[i = i++ == 3 ? 0 : i]);
 System.Threading.Thread.Sleep(250);
 }
 }
}

Yes, I'm probably very late, but I had to post it..!

EDIT: I figured someone else posted a 109 byte C# solution, oh well
EDIT 2: Thanks to the poster of the 109 byte C# solution, I managed to lose 3 more bytes by removing i<4 from my for loop, thanks!
EDIT 3: Removed C# 6 string interpolation and used good old + instead to save 2 more bytes.
EDIT 4: Not declaring a var for the animation characters anymore, instead I added them directly into the Write() method, saving another 8 bytes
EDIT 5: Removed the parameter string[]s from the Main method to save 9 bytes!
EDIT 6: Used carriage return instead of System.Console.Clear(), removed a using and moved the incrementing of i + the ternary inside of System.Console.Write(), all thanks to @CSharpie! (all this saved 21 bytes)

• CSharpie: Instead of Console.Clear just use a carriage return infront of the string. c.Write("\rLoading... "+@"|/-\"[i]);. Then you probably can further reduce by getting rid of the using since you only need System.Console.Write("\rLoading... "+@"|/-\"[i]); You can put your ternary expression in there too, making it System.Console.Write("\rLoading... "+@"|/-\"[i=i++==4?0:i]); whilst also removing the i++ from the for-loop.
• CSharpie: One small mistake, cant edit comments after 5 minutes so: Console.Write("\rLoading... "+ @"|/-\"[i=i++==3?0:i]); resulting in 142 bytes.
• Mika: Woah @CSharpie that's some awesome improvements, thanks alot! I'll apply some of them, but I will have to explain why I rolled back the carriage return (I added it earlier): imgur GIF this is happening when the console window isn't wide enough, somehow. Doesn't happen using .Clear()
• CSharpie: thats nothing you need to worry about.
• Mika: @CSharpie Oh, really? I'll apply that as well then! Thank you very much :) I also discovered a weird exception happening using .Clear() but I don't think this is the right place to discuss that, so I posted it on SO instead

Answer 18

Python 3, 94 bytes

Okay. First answer. EDIT: SAVED 8 BYTES EDIT 2: SAVED 1 BYTE EDIT 3: SAVED 11 BYTES EDIT 4: SAVED 3 BYTES EDIT: SAVED 5 BYTES EDIT: SAVED 2 BYTES

import time
while 1:
 for f in 0,1,2,3:print("Loading...","|/-\\"[f],end="\r");time.sleep(.25)

Ungolfed:

import time
while True: # Loop forever
 for f in [0, 1, 2, 3]: # Loop four times
 print("Loading...", "|/-\\"[f], end="\r") # Print Loading... then the current frame
 time.sleep(0.25) # Wait 0.25 seconds

• FlipTack: Welcome to PPCG! Nice answer, although there is a shorter python solution here. You might want to see tips for golfing in python so you can make your future answers shorter :)
• Wheat Wizard: I see you have a bit of extra whitespace particularly f += 1 can be replaced with f+=1 and f >= 3 can become f>=3. Additionally 0.25 can be replaced with .25
• Wheat Wizard: Also I think a can be defined as the string "|/-\\" without any issue. And since a is only referenced once you don't have to define it at all.
• Wheat Wizard: Another thing I noticed is the fourth line is the same as f%=3.
• Wheat Wizard: While True: is the same as While 1:

Answer 19

PHP, 56 bytes

while(!usleep(25e4))echo"\rLoading... ",'\|/-'[@$i++%4];

Answer 20

JavaScript (ES6) + HTML, (削除) 77 (削除ここまで) 74 bytes

f=c=>setTimeout(f,250,-~c%4,o.value="Loading... "+"|/-\\"[~~c])

<input id=o

---

Try It

(f=c=>setTimeout(f,250,-~c%4,o.value="Loading... "+"|/-\\"[~~c]))()

<input id=o>

Answer 21

C++ (224)

This certainly isn't the shortest code to do this. I like doing coding challenges, so I'm posting it anyway.

#include <iostream>
#include <string>
#include <thread>
using namespace std;int main(){string s = "|/-\\";int i=0;cout<<"Loading... ";while(1){cout<<s[i];this_thread::sleep_for(chrono::milliseconds(99));cout<<"\b";i=++i%4;}}

• Wheat Wizard: You can save 2 bytes by removing the spaces around =.

Answer 22

><> with -t.03 flag, 33 bytes

'o!vooooo|\-/ ...gnidaoL
{[4<o8o:

Try it online!

The only part of the specification this doesn't implement is that the first frame should be printed as soon as the program is run which seems rather strict and unobservable. The first frame here take 1.08 seconds to print, and every frame after that takes 0.24 seconds.

Answer 23

Python 3 (Windows), (削除) 112 (削除ここまで) (削除) 109 (削除ここまで) 108 bytes

import time,os
while 1:
 for i in ['|','/','-','\\']:print("Loading... "+i);time.sleep(1/4);os.system('cls')

Python 3 (*nix), (削除) 111 (削除ここまで) 110 bytes

import time,os
while 1:
 for i in ['|','/','-','\\']:print("Loading... "+i);time.sleep(1/4);os.system('clear')

Thanks @Dion for reducing 3 bytes in Windows version and add more info about *nix run!

• Dion: You could save 3 bytes by moving the last line onto the previous one
• Dion: You could also change 0.25 to 1/4 to save a byte :p
• MarcMush: save a bunch of bytes with for i in '|/-\\':print(end="\rLoading... "+i);time.sleep(1/4)

Answer 24

CLC-INTERCAL -psyscall, 356 bytes

Uses latest feature: syscall #9.

DO;1<-#12DO;1SUB#1<-#94DO;1SUB#2<-#317DO;1SUB#3<-#314DO;1SUB#4<-#2567DO;1SUB#5<-#377DO;1SUB#6<-#364DO;1SUB#7<-#248DO;1SUB#8<-#670DO;1SUB#9<-#188DO;1SUB#10<-#255DO;1SUB#11<-#255DO;1SUB#12<-#213DO;2<-#1DO:9<-#392¢#452DOCOMEFROM#9(4)DO;2SUB#1<-#122(2)DO;2SUB#1<-#126(1)DO;2SUB#1<-#15DO;2SUB#1<-#47DO.1<-#8DOCOMEFROM.1DOREADOUT;1+;2(666)DO.9<-#9(9)DO.1<-.1~#14

Running gif before fixing; spinning counterclockwise

Running CLC-INTERCAL program on Termux.

Ungolfed

DO;1<-#12 DONOTE ;1 <- "\rLoading... "
DO;1SUB#1<-#94
DO;1SUB#2<-#317
DO;1SUB#3<-#314
DO;1SUB#4<-#2567
DO;1SUB#5<-#377
DO;1SUB#6<-#364
DO;1SUB#7<-#248
DO;1SUB#8<-#670
DO;1SUB#9<-#188
DO;1SUB#10<-#255
DO;1SUB#11<-#255
DO;1SUB#12<-#213
DO;2<-#1 DONOTE ;2 is one of "|/-\"
 DONOTE implicit .1<-#0 as iterator
DO:9<-#392¢#452 DONOTE const 250,000
DOCOMEFROM#9
(4)DO;2SUB#1<-#122 DONOTE /
(2)DO;2SUB#1<-#126 DONOTE -
(1)DO;2SUB#1<-#15 DONOTE \
DO;2SUB#1<-#47 DONOTE |
DO.1<-#8
DOCOMEFROM.1 DONOTE possibly from 4 2 or 1
DOREADOUT;1+;2
(666)DO.9<-#9 DONOTE sleep for :9 microseconds
(9)DO.1<-.1~#14 DONOTE right shift

Answer 25

YASEPL, 122 bytes

=sŔ,9=1)pipesdividesminuss"\"=b27ドル»sopenbracket=o|3`1!aŔ,9!c$a-s}1,250,3|`3!b~#"2J"~#"HLoading..."=g\o,1~!o+%4!Ŕ,9|

it starts automatically, the compiler just takes a second to load the file so thats why there is a pause if you run this

I cant exactly make a GIF of this right now, but when I can i'll update.

this uses ANSI.

Answer 26

Easyfuck, (削除) 41 (削除ここまで) 36 bytes

ymsĘ·^U¶ąĺw‹ž]€ ĎÁ␆n␈2 ́A•ŕ␐.\»>í90ďSOS

^{due to lack of unicode representations for c1 control characters, they have been replaced by their superscripted abbreviations}

Decompressed:

<[.<U]<U[.<W<.<]@␈␙|␈␙\␈␙-␈␙/␀ ...gnidaoL

the gif

<[.<U]<U[.<W<.<]@␈␙|␈␙\␈␙-␈␙/␀ ...gnidaoL
< go to the last cell
 [.<U] go through cells backwards, printing and deleting until encountering a null character
 <U delete the null character
 [.<W<.<] go backwards through characters looping when reaching the beginning, printing and waiting according to their values
 @ marks the end of code
 ␈␙|␈␙\␈␙-␈␙/␀ ...gnidaoL initializer data

• noodle person: Is your code using raw EM and \ bytes, and you are using the unicode versions just for presentation purposes? If not, this is 59 bytes in UTF-8
• Quadruplay: @noodleman they're raw bytes, i had to use powershell to push them into the file one by one and then i replaced them for presentation purposes

Answer 27

Uiua, 39 bytes

⍢(&sl1/4&pf⊂"\rLoading... "⊢.↻1)1$ |/-\

program running

For some reason it looks really slow in the GIF but I can assure you on my computer it waits for 1/4 of a second. You may also notice that in the GIF, the code has an extra backslash; that's because I have Uiua 0.9.5 installed on my computer. In 0.10.0, the way $ strings work is a bit different, and the extra backslash isn't needed.

Explanation:

⍢(...)1$ |/-\

This starts with "|/-\" on the stack and does the rest of the program in a loop forever. A byte is saved by using the raw string syntax $ |/-\ instead of the normal "|/-\\".

↻1

Rotate this string one character to the left.

&pf⊂"\rLoading... "⊢.

Combine the first character of this with the loading text, and print it. The \r causes the text to be printed over whatever was already there.

&sl1/4

Sleep for a quarter of a second. Using a fraction literal like this is a byte shorter than 0.25.

Answer 28

GNU AWK, 86 bytes

Run it on your terminal:

gawk -ltime 'BEGIN{for(printf"Loading... |";sleep(1/4)++k;)printf"\b"substr("|/-\\",k%4+1,1)}'

Try it online!

80 chars of code + 6 chars for arguments

This is just GNU AWK relying on its time extension and respecting all rules. No input, no BASH, no coreutils. Could be shorter, but the sleep function must be called after the first printf.

gawk -ltime Runs GAWK with time extension.
 Exactly the same as using @load "time", but shorter.
'
BEGIN{
 for( Begins the loop without input.
 printf"Loading... |"; Starts printing the first iteration without trailing line.
 sleep(1/4)++k; Waits .25 second, which returns 0, and appends to the counting variable.
 No big deal here. I just did it to save characters.
 ;)
 printf
 "\b" Prints a backspace
 substr("|/-\\", appended to a sub-string of this monstrosity (\ is escaped)
 k%4+1, starting at the character mod 4 + 1 (GAWK starts counting at 1)
 1) with length 1.
'

Answer 29

Casio BASIC (fx-9750GIII), (削除) 64 (削除ここまで) 60 bytes

"Loading..."
Lbl A
1+Ans Rmdr 4
Locate 12,1,StrMid("\\|/-",Ans,1)
For 0→I To 200
Next
Goto A

The timing is probably not accurate since the Casio fx-9750giii doesn't have any built-in time functions as far as I know, but I think I got pretty close.

Timing ranges on what device you use this on, since it uses a for loop to separate the frames.

Answer 30

tcl, 83

while 1 {lmap c {| / - \\} {puts -nonewline \rLoading...$c;flush stdout;after 250}}

Can be seen running on: http://tpcg.io/_6PBTFX

Unfortunately, this online compiler can not demonstrate it going back rewriting the line. In a local machine it can be seen.