Pointers - Go Lang Practical Programming Tutorial p.4

Key Takeaways

what is going on everybody welcome to part 4 of the go tutorial series in this part what we're really talking about is pointers which is pretty much the last element that's going to be necessary for you to understand the basic kind of go web server example so also if you're like coming from something like Python this is totally foreign to you so so it's probably a good idea we cover it so the first thing I'm gonna go ahead and do is kind of clean up what we've got going on here so first of all we're just gonna be using format so I'll get rid of the parentheses there we'll clean up these two functions and I'll just empty out main because we don't need anything there alright so let's say we have a variable and we're gonna say it's X colon equals and we'll say that if X is equal to 15 what type is 15 you should know now now what we can say is a colon equals and that's going to point to X so the way that we point to something is with the ampersand and then the variable we want to point to so this is gonna wind up being the memory address I'll just write that out and then now let's go ahead and format dot print line a just so we can see what we're doing so let me bring up a command line and go run go go boom so that's actual memory address where the value for X's is being stored so now what we can do is like what if we so so basically you if you want to point to something use the ampersand but if you want to read through a memory address you use the asterisk or star so so what we could say is format dot print line asterisk a save that run that and you see in this case you get 15 because that's that's currently what the value of x is now what if we said asterisk a equals 5 what what do you think we'll wind up happening there so let's go ahead and save that run that whoops we didn't anything else let's go ahead and print X now so format dot for its line X so now X is actually equal to five because it's changed so so now like just just for fun a the reading through of that memory address of X so the reading through of whatever's at a equals whatever's through at a times every through day that looks fun so what's gonna be the output there right you should be able to visually look at this and know what's what's gonna say but oh we still need to print it out huh let's print let's do format dot print line X what happened hey there we go we're Matt dot print line X and then also let's let's print out asterisk a and that's probably so we'll save that we'll run that and as you can you probably could have guessed it was going to be five times five but anyways pretty cool it's it's super simple once you get used to it but it as a foreign concept it gets kind of challenging just know that anytime you've got ampersand that's the memory address that's leading to whatever variable you pass and then if you want to read what's at that variable or what's at that memory address rather you're gonna use the asterisk alright so that's all for pointers and in the next tutorial we'll actually start with our super basic web server example if you have questions comments concerns whatever you can feel free to leave them below otherwise I will see you in the next tutorial