Difference between GoSub & Goto?

[Sam71]

Hi,

I was just wondering what the difference is between the commands "GoSub" and "Goto"?.

[Dorian (MJT support)]

Goto will jump to a label and carry on from there, missing out everything inbetween. So:

Code: Select all

MDL>Hi
Goto>Jump
MDL>This line will be skipped
Label>Jump
MDL>And carry on from here.

Whereas Gosub jumps to a Subroutine - a self contained section of code - executes all the code in that subroutine, then goes back to next line after the gosub. This is useful if you have certain code you use a lot. You don't have to keep repeating it. I know you use Image Recognition a lot, so you could, for example, use it to look for a certain image wherever you used it in your script, without needing to use the same Image Recognition code over and over. Like this :

Code: Select all

Gosub>LookforImage1
..do something else
Gosub>LookforImage2
..do something else
Gosub>LookforImage3
..do something else
//look for image 2 again
Gosub>LookforImage2

SRT>LookforImage1
  FindImagePos>%BMP_DIR%\image_1.bmp,SCREEN,0.7,1,XArr,YArr,NumFound,CCOEFF
If>NumFound>0
  MouseMove>XArr_0,YArr_0
  LClick
Endif
END>LookforImage1

SRT>LookforImage2
  FindImagePos>%BMP_DIR%\image_2.bmp,SCREEN,0.7,1,XArr,YArr,NumFound,CCOEFF
If>NumFound>0
  MouseMove>XArr_0,YArr_0
  LClick
Endif
END>LookforImage2

SRT>LookforImage3
  FindImagePos>%BMP_DIR%\image_3.bmp,SCREEN,0.7,1,XArr,YArr,NumFound,CCOEFF
If>NumFound>0
  MouseMove>XArr_0,YArr_0
  LClick
Endif
END>LookforImage3

Try experimenting with this very simple example in the editor, with >Debug >Trace so you can see it run line-by-line

Code: Select all

Gosub>MySubroutine
MDL>Now I am back up here
Gosub>MySubroutine

SRT>MySubroutine
  MDL>I jumped down here
END>MySubroutine

[Sam71]

Goto will jump to a label and carry on from there, missing out everything inbetween. So:

Code: Select all

MDL>Hi
Goto>Jump
MDL>This line will be skipped
Label>Jump
MDL>And carry on from here.

Whereas Gosub jumps to a Subroutine - a self contained section of code - executes all the code in that subroutine, then goes back to next line after the gosub. This is useful if you have certain code you use a lot. You don't have to keep repeating it. I know you use Image Recognition a lot, so you could, for example, use it to look for a certain image wherever you used it in your script, without needing to use the same Image Recognition code over and over. Like this :

Code: Select all

Gosub>LookforImage1
..do something else
Gosub>LookforImage2
..do something else
Gosub>LookforImage3
..do something else
//look for image 2 again
Gosub>LookforImage2

SRT>LookforImage1
  FindImagePos>%BMP_DIR%\image_1.bmp,SCREEN,0.7,1,XArr,YArr,NumFound,CCOEFF
If>NumFound>0
  MouseMove>XArr_0,YArr_0
  LClick
Endif
END>LookforImage1

SRT>LookforImage2
  FindImagePos>%BMP_DIR%\image_2.bmp,SCREEN,0.7,1,XArr,YArr,NumFound,CCOEFF
If>NumFound>0
  MouseMove>XArr_0,YArr_0
  LClick
Endif
END>LookforImage2

SRT>LookforImage3
  FindImagePos>%BMP_DIR%\image_3.bmp,SCREEN,0.7,1,XArr,YArr,NumFound,CCOEFF
If>NumFound>0
  MouseMove>XArr_0,YArr_0
  LClick
Endif
END>LookforImage3

Try experimenting with this very simple example in the editor, with >Debug >Trace so you can see it run line-by-line

Code: Select all

Gosub>MySubroutine
MDL>Now I am back up here
Gosub>MySubroutine

SRT>MySubroutine
  MDL>I jumped down here
END>MySubroutine

Hi Dorian,

Am I right in thinking that the gosub runs faster than say the other types of loops like goto etc?. I'll be testing this out ASAP.
Thanks,
Sam

[Dorian (MJT support)]

Tbh I'm not sure there'd be any difference, speed-wise. In my opinion they are more convenient if you're using the same routines over and over.