Using String and Numerical Data Types with C # Code in Visual Studio! Beginner Programming Tutorial

what's going on you guys welcome back to the channel and today's video is going to be a discussion of the string and numerical data types within c sharp [Music] so today's video is going to be the second video in our introduction to c-sharp tutorial series and if you are a complete beginner to c-sharp like you still need help downloading microsoft visual studio or any ide knowing what to install and how to open your first console.net app then i recommend you check out the first video on the channel otherwise we're going to get into some pretty beginner c-sharp concepts in this video hope you enjoy it so to start with i always just inside my function i'll put this right line read line because those are pretty typical input and output instructions but to get started i just want to create a string variable so we talked a little bit about variables in the first video but if this is your first time seeing this that's fine too so to define a new variable and define it as a string you start by typing the word string and then you type the name of the variable that you want it to have i'm going to call my string my string and then you set an equal sign and then you use the two um the two quotation marks to identify that it's going to be a string and this is an important difference between c-sharp and like python because in python single quotes and double quotes it doesn't make a difference it does in c-sharp if you use single quotations it's a character and you can only put one letter or number in there but if it is a two quotations then it's a full string and you can have as many text letters as you need and so inside the quotations you can put your text so i'll just say pete rocks because that's good text and so now if i'm going to go ahead and use my right line i'm just going to display my string and then the read line is only here to slow the program down so that we can actually display it but if i go ahead and run this we get pete rocks on the console window okay so that's great and if i were to hit enter then that's going to finish the read line and then our code is going to close or you can hit the x whatever but so this is just me putting in a variable because it's easier you could also pete does not rock you can also type a string directly in the right line output and so if i were to run this you'll see we're not using my string anywhere anymore we're just using that text directly that's valid too but a lot of the concepts i want to show you in this video are going to require um a variable your string being stored somewhere so we're going to go ahead and put it in my string and i think the next thing i want to talk about are just a couple special characters so um if you want a new line so say i wanted rocks to be on a second line it's backslash n and you should see if you're using visual studio and if you still have it on default text editor settings which i would recommend for beginners when you do backslash n it turns yellow because it's a special character um but so now if i run this we get pete and then we get rocks on the next line and that's because backslash n is our new line special character a couple other things if you want a quotation mark so if i wanted pete to be in quotation marks well the problem is it thinks that a quotation is either the start or end of a string so what you do is backslash again and then quotation marks and then you would do the same thing at the end so backslash quotation marks and that should turn yellow as well it's just a special identifier saying take this thing that normally would not just be a string character and make it a string character and so the last one i want to touch on since we're here is if you want a backslash you do two backslashes straight just like that and that's going to write just one backslash onto the screen okay so those are all kind of special cases you may want quotations you may need a backslash and you may need a new line at some point so those are just good to know um okay so the second thing i want to talk about is concatenation so if i were to make a second string i'll call it second string and in this one i will say but not that much now i have these two strings and if i want to display them both i can do it a couple different ways and the easiest one is just where i'm displaying the first string use this plus and then type in second string and this is called string concatenation so anytime you combine multiple strings it's called concatenating your strings that's just what's called you can call it string combining if you want and what you'll see is they actually smush right together because we don't have a space built into that so what you could do is you could put a space at the end of one string or you could put a space at the start of the second string either way it kind of looks weird just on its own so what else you could do is you could do a plus and then two quotations and then just a space and this is you manually inserting a space character into your string concatenation but now you can see it looks good okay so that's a little bit about string concatenation that's a little bit about um strings in general but now let's start looking at things that you can use with strings so um everything we're about to use is called a method so it's like a built-in string manipulation or an analysis tool that c-sharp and visual studio have built in so the first method i'm going to talk about is length so if i type in my string which is pete rocks and i do dot and then length and you'll actually see right away when you put in a string and then a period you see if you're using an ide like visual studio a good modern one it shows you all of the built-in methods that you can use to manipulate strings so we're just gonna do a few simple ones today a few common ones but you can always scroll through there and look if you're looking for a more advanced function it could good chance that it shows up in there so the first one we're going to show is just my string dot length and that's all you have to do right there and what you're going to see is it's going to tell us how many characters are in this string so this is five and that'll it should show us 10 i think there we go so it shows us 10 and that's because space counts as a character but one thing i want to show you if you have those special characters so like backslash n for a new line this will still work it's just going to tell you 11 and you may notice we added a backslash and an n and it only added one character that's because backslash n is considered one character so is backslash quote backslash backslash they're all special characters but in terms of length it's just viewing that as one character so that's the dot length a lot of the times you can use this in things like a password checker to make sure you meet the minimum length requirements things like that okay so the next thing i will talk about uh the next method is if you want to make sure you have a specific case so let's say instead of pete rocks this was the master tech okay and i'll get rid of this second string for now because we're not using it so if you had something where you wanted to pass um all of the the the string in but you want it to be all uppercase there's a built-in method for that it's string dot 2 upper like that and then you need to add parentheses right there and so if i go ahead and run this you'll see we get lemaster tech all caps that's pretty good and you probably could guess there's also two lower just like that and that's going to give us the master tech a lowercase great um so that's two upper two lower and then the next thing is you can check if a string contains a subset of that string so i'm gonna go ahead and just say let's say it was checking just for the master and this is going to return just a true false so there you see we get true because it's in the master tech but a couple things about this if it is case sensitive so if you were to check le master spelled that way it's going to say false even though those letters are in there so what you could do is you could combine something like two upper and the contains statement to uh to kind of combine these operations so you could say contains and then two upper of my string and then all caps lemaster if you don't care about case but just know that this is case sensitive and then it's also if you were to say well the master's in there but le masters is not then it'll still tell you false it needs to see everything that you put inside of this is in there okay so that's useful now uh the next thing i want to talk about is the index of individual characters so if you have my string and you want to look up specific character um you use these square brackets and then you put in the character that you want to see so let's say i'm trying to get a hold of this capital m the counting actually starts from zero not one so l even though it's the first letter its index location is zero if you're familiar with software or programming concepts the the first bit the first location of anything is typically referred to as a zero not a one so actually counting up zero one two would give us the capital m so let's go ahead and run that and you can see we get a capital m on the screen okay so that's indexing you can you know you can index anything i'll index five here and we'll get lowercase t so that's um it can just be useful sometimes to look up the first character of a of a string or anything like that when you don't care about actually the whole string um all right so another thing since we're talking about the indexes is you can use this concept index of and then you can look up where an actual sub string exists so we let's say we want to know when the word text starts okay so it's going to tell you the index of wherever it shows up inside of your thing so tech starts at the ninth character which if we count zero one two three four five six seven eight is the space nine is the capital t it gives us a 9. that's great something to note if you have multiple of a letter though so like lowercase e there's three of them it's always going to give you the first index so once it finds your letter it's gonna just give you that value and then leave so that's the index of it's uh pretty useful and so let's go ahead and talk about the substring now so this is another very common method and what you do here is you use that index value and if you only put one value in what it's going to do is it's going to go to that index so 0 1 2 3 4. it's going to go to s and that's just going to give you the remainder of the string starting from there so you can see we get ster space tech but there's a second thing you can do with the sub string which is you can also give it a length so let's say we want to be six characters long if we go in now we just get s t e r space capital t so this is how you grab a portion of your string um without modifying the whole string and that's the dot substring method okay so these are a bunch of really useful string concepts that it's just great to know but we're going to go ahead and move on and talk about number concepts now because it's very similar so as we talked about in the previous video but if you don't remember that's okay so if you use int that's a whole number integer value so that has to be something like 1 2 3 4 5 6 12. doesn't matter has to be a whole number it can be negative it can be zero but it can't have decimal places if you do want to use decimal places there is float decimal and double i recommend just sticking with double for all common especially beginner concepts really accurate numbers a double is going to be fine for you and so for a double you can say we'll say my number because we're going to get rid of integer for a double you can have decimals you can say 32.5 things like that and actually so i'm going to go ahead and get those console.writeline and readlines back console.writeline console.readline just because most of what we're talking about gets a lot better if we can display it on the screen so just like before you could just um you can just put a number in your right line and show that on the screen and if i run this it works fine it shows me 35.8 um but it's typically if you're using the number somewhere in your function in your program you're going to want it in a variable because that way you can actually store it somewhere um okay so uh we're gonna talk about a lot of the um methods underneath numbers now because they're not it's not exactly the same there are a few things that you can do after if you press dot but mostly it's like comparing and um to string and checking for equals and those are actually not as important when you're dealing with numbers as mathematical operations are so what i'd like to do is i'd like to do a second here console.writeline because we're going to come back to my number and we're going to use it a few times but i'm going to do a console.writeline and type in capital math math so that is like the math module inside of c sharp and visual studio and if you use a period after that you're going to see tons of common mathematical functions uh you've got trigonometric things like cosine sine and tangent logarithmic functions exponential functions we're going to talk about some of the most common ones real quick so one of the ones that pops up all the time is abs and that's just absolute value so if you're familiar with an absolute value it takes whatever your value is and it gives you the positive return of that so if i put minus 17 in here you can see we just get positive 17. it also works on mathematical operations so if we had like minus 17 times 2 so that's negative 34 it's going to do the math for us 34 and give us the absolute value and i should have mentioned that here as well so like my number plus 12 it can do this math just built in intrinsically and you're gonna see even though our number was 32.54 it adds 12 to it and displays 44.54 okay so you can do plus minus multiplication is the star and then division is the forward slash you can do any of those right in this statement or you can do something like um double and then my math number all right no no call it whatever you want um but you could you could intermediate you could save the value of the operation that you're doing into an intermediate variable so if you wind my number divided by 11 you could store it in my math number and then you could display my math number okay so that's gonna be like just shy of three five eight um so this is another way of doing it you could just do this math if it's not too complex write in your right line statement or write in your output wherever or you can store it in an intermediate variable this is probably a little bit cleaner in general having a variable to store your math is is a good place to do it okay so that was just a little tangent let's go ahead and just change this back to my number and i'm going to keep showing you some methods inside the math module so another super common one is pow which is basically raise a number to a power so let's say something that we can verify we want to raise two to the fourth power okay all you do inside of the pow function is you say what number it is that you putting an exponential value on and then what power you're raising it to so 2 to the fourth is 16. 2 times 2 is 4 times 2 is 8 times 2 is 16 okay that was quick math um but so this also works with decimal values um so 2.4 to the fourth would still work just fine uh it also works on believe negative exponential values so yeah 2.4 to the negative fourth is .03 who knew um so yeah this works with negative x exponentials it works with decimal values uh the pow function is super useful and pops up all the time next sqrt is square root so that's just giving you a square root of a number it's the kind of the opposite of the pow and so there you can see square root of 36 is 6. 6 sqrt we'll do min max and round next and then we'll actually get into some fun like code so min is a useful one for returning the lesser of two values and this can be decimals or integers or i believe a mix so yeah you'll see if i put in min between 12 and 89.5 it's going to tell me like the minimum is 12. but if i take this exact same line and i change that min to max it should tell us well 89.5 is your max value so there you go um min and max there's a ton of times inside of python c sharp inside of visual studio and c sharp where you're actually going to be comparing multiple values selecting the larger or the smaller of the two to continue with so that's a super useful concept and then the last method i want to talk about inside of the math module is just round and you're probably familiar with like standard rounding rules for your um for your function but let's say you had 17.9845 um so obviously that's pretty close to 18 you would expect it to round and there you go to 18. if you uh put it right at 17.5 it is gonna round down um oh 17.5 round it up okay make me a liar code um let's see 17.49 rounds down okay interesting because i swear i had 17.5 earlier rounded down that's cool if you have 17.5 it's gonna round up every time uh okay so the round function super useful to know um i believe if you do um a comma and then you uh put an integer there you can select how many decimal points you want to round to so it doesn't have to round to a whole number so if you have 17.523 and you want keep two decimal points it'll round to that second decimal point if you had like you know something goofy and you want to round to four decimal points uh you can do that just by adding a comma adding a second argument so that's super useful um in actually like grabbing the amount of data that you have a level of confidence in and that is really those are the most key things i wanted to talk about inside of the math module so let me just say two more things about like built-in functions that are going to speed up your programming so there's a way to increment your number without having to do the long form of this which would be my number equals and then whatever my number currently is plus one okay and what you'll see because we've got 32.54 here that's going to give us 33.54 which is what we want but there's a faster way and it would just be my number plus plus and you're going to use this all the time for things in like for loops and integer uh while loops as like an incrementer value so you'll see there just by changing it to plus plus it still gives us plus one and that's a lot faster than plus you know my number equals my number plus one and then obviously the inverse of this you can do minus minus and that's going to negate one so it'll go from 32.54 to 31.54 okay so uh super good to know all of these things about numbers um one quick thing if you do have a double and an integer so i'll call this one whole number and it's equal to three and you multiply the two together or you divide them or you add them or anything if you have an integer and a decimal number and you combine them it's always going to give you an output of the double it's always going to give you the decimal the more accurate value so 97.62 when you multiply the two together but a really important thing to know is if you have two integers and you do something that should give you a decimal value so let's say my number divided by whole number right 13 divided by 3 should be like 4 and a third so 4.333 because we're using two integers it's not going to give us an integer out a decimal output it's going to give us an integer output so the way around that is just make one of them instead of an integer make one of them a double and that way you just do 3.0 or you could do i think i think you can do three and it's still going to give you a decimal answer so you don't have to type this point o in you can if you want to remind yourself it's not an integer anymore um but yeah so there's that super useful tip the last thing i want to talk about the modulus operator or modulo operator one of those it's basically division but then checking for the remainder so it's basically a remainder operator so 13 divided by 3 is 4 with a remainder of 1. if i run this it gives us a 1. now 14 divided by 3 is still is still 4 but now the remainder is 2. so if i show that it gives us the remainder of two there's a whole bunch of times in programming you're going to want to make sure that one number fits evenly into another number so in that case you would check that something was essentially like division you'd check that the modulus was equal to zero that's how you could make sure something divides evenly into something else okay so this was a crash course in strings and a crash course in numerical data types and i hope you found it useful and if you do have any questions feel free to ask them in the comments below if you did find it useful please leave a like on the video subscribe to the channel it helps me out a ton and the next step in our tutorials we're going to take everything that we've learned and talked about and turned into like a four function calculator so stay tuned for that be on the lookout for it and that's really going to be the next step in learning c sharp so thanks so much for watching and good luck with your code thanks bye