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‫Welcome back.

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‫And this video, we are going to look at string and some of its methods.

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‫So String is an object of the system string class.

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‫And here in programming terms, string just means a sequence of characters.

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‫And there are a bunch of functions that are inside of this class that we can use in order to manipulate

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‫a string.

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‫And now let's have a look at some of those.

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‫So let's look at, for example, substring.

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‫So substring requires an integer when you want to call this function and it is used to get the substring

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‫from the string starting from the specified index.

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‫So if you take, for example, a string called car and you enter substring one, what it will do is

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‫it will just return R, which means the C will be taken away because we are not starting at zero, but

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‫we're starting at one.

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‫So basically every single character has an index and for example, C is at zero, A is at one, R is

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‫at two.

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‫So if we say substring one, it will just take a R instead of taking the whole car.

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‫Then we have to lower that is used to convert the string to lowercase.

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‫So whatever is written inside of the string will now be converted into being a lowercase sentence or

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‫string at the same goes forward to upper but the other way around.

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‫So now it's going to convert the string to uppercase.

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‫Then we have the option to trim our string so that it is trimming, all leading and trailing whitespace

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‫from the string.

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‫So this is often the case when entering an email address inside of a form where you, for example,

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‫by accident, have an empty space at the end when you copy it from somewhere.

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‫And that is usually done by the website itself or by the form itself.

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‫So you don't have to delete the white space at the end because white spaces don't really add any value

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‫in email addresses, right?

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‫So that's why they are taken away.

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‫They're by using the trim function, for example.

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‫All right.

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‫So now let's look at some other methods.

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‫So, for example, index of string that is used to get the first occurrence of the string or character

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‫inside of another string.

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‫So if you have a sentence and you want to know at which position a certain word appears, so at which

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‫position inside of that sentence, then you can use index off.

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‫Is now a white space returns true if the string is either null or is blank.

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‫Else it returns false.

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‫So this is useful if you want to check if a string has any meaningful value or not.

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‫All right.

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‫So now let's look at some functions here.

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‫So, first of all, I have the first name called Dennis, the last name Pun, and then the full name,

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‫which is concatenated.

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‫So we are using the function cat which concatenate those two strings, which basically just puts them

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‫together.

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‫Okay.

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‫So then we have Dennis punch, then we use the substring function and we give it a value of two.

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‫So the output will be nice because zero what was the D?

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‫One is the E and it starts from two, which is N, so it just gives us the rest of the string, which

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‫is nice.

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‫Then we have to lower which will output dennis so the dx will be lowercase now instead of uppercase

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‫and the other way around.

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‫So here to upper will just make the whole string an uppercase string as well as trim.

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‫We'll just go ahead and trim all of the white spaces that we have here.

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‫So the output will be ten is Pangea.

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‫So it takes away those empty spaces that we have surrounding it.

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‫So here for example, I'm using an empty space as well as here I also have an empty space.

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‫And then we have the first name dot index of E and the output will be one because EA is at the position

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‫one of the first name variable which is Dennis.

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‫So D is at zero, EA is at one.

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‫There we are and then is null or whitespace with the first name will output false?

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‫Then there is another important method which is called format.

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‫So in C-sharp, the string format method is used to insert the object or variable value inside any string.

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‫With a string format, we can replace the value in the specified format.

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‫So here for example, syntax is string dot format any string with the index comma object.

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‫So what that will do is it will put the object into the position of index so it will replace it.

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‫So let's look at an example here.

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‫So we have our name, which is Dennis.

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‫So this is a string that we have here and then we use string format where I just say my name is.

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‫And then in those curly brackets I have zero and after the string I have comma name.

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‫So name itself is also a string.

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‫So here the string name will be replaced at index zero in the string and the output will be my name

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‫is Dennis.

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‫So we can basically just take variables and put them into a string by using the format function here.

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‫This will come in very handy and we will use it every now and then.

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‫All right.

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‫So that's it for now.

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‫Let's get back to coding.

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‫See you in the next video.