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Hey there, this lesson is going to be all about string methods in JavaScript, looking at trim, charging

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the case to upper, lower case, splitting, slicing, replacing, lost index of index of.

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There's a lot of options when it comes to strings covering those within the section.

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So string methods, they allow you to update and manipulate string values.

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You can search, you can slice.

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So there's a lot of things that you can do that is similar to what you can do with the race where we

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do have a paragraph here.

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So we've got a string value here.

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We can search for a particular term and then look and find the index value of that term.

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You can also see that we can get that back so we know which the index value is and where it's occurring

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within the string.

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So it's finding the first index value of its returning back, just that one.

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There's also some additional options with strings.

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And as you can see, there's quite a bit that you can do with string methods.

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There's a bunch of examples here where it's looking for index value of blue.

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So it's returning zero if it's not finding it.

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So because blue is the first value within the string, if we're looking for blue, it's going to return

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back a negative one.

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So that means that it wasn't found within the string, if we're looking for well, comma zero.

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So it's going to return back five, which is going to be the first character of Blue Whale is if we're

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looking at well, five, we're also going to be returned back five.

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So this is a parameter that you can pass in because the whale is starting at five.

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But if we start at seven, then we're going to get a negative one because it's not going to be able

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to find that within the.

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And here's another example of checking to see if Blue is contained and noticed that it is case sensitive.

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So blue lowercase is not the same as blue uppercase.

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So it's going to be returning back a negative one.

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And we're also can check to see if it doesn't exist.

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So if we're not getting a negative one because it does exist.

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So it's true.

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And as you can see, there's a number of ways to check so you can have negate it as well as equal to

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negative one and a number of different ways to check to see if something exists within a string.

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Some more examples.

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So in this example here, it displays four because E is within the fourth position index value of that

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particular string value.

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Let's try this out within our ED.

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So now let's create a string in the ED.

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And this can contain any content that you want.

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You can search for the same values.

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And I'm going to be looking for create your own string.

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And I have some numbers in there and we'll repeat JavaScript twice so I can show you that there are

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different ways if you want to return back several different words within that string.

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So refresh and we've got my string value output.

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It it is definitely a string value in there.

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We can get the length of the string.

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So doing length we can see how many characters are contained within the string.

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A lot of these all out into the console.

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So my string getting the length also trim the string.

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So if for instance we've got some spaces in the front and in the back, we can use the trim method and

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what that will do is that's going to remove out all of that white space there.

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So see that now we've got the trimmed version of it using the my string trim, whereas if we just put

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out the string, you can see that it is slightly different.

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So we've got all of the white space and that one, there's no white space in this one.

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So that's what trim can do it.

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It allows you to trim your string.

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You can also convert it.

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So converting the case so there's two uppercase to lowercase, so using to lowercase that will turn

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all of the string values to lowercase.

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As you can see in the example, you can also use several of them together if you want to.

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So trim and trimming them, as well as converting them to lower case, you can chain them together in

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that format.

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There's also, as we saw, lowercase.

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And then there's obviously there's uppercase as well.

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So we can convert it to uppercase and they'll do the same thing, except it will do the opposite.

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Return all of the string values to uppercase.

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We can also split string values.

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So we've got our string that we've been using and if we want to split it into an array, so splitting

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it by the spacing.

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So this will split out all of the words into an array.

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And this is a useful function because then you can use this in order to search out for different words

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or you can loop through them.

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And then you could apply a bunch of the array methods that are also really super useful.

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So turning a string into an array, this is a great one.

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How you're splitting up so you can split it by commas or you can split it by different letters.

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So whatever works.

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So in this case, we split it by the comma.

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If I want it to, I could take a character.

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I could split it by that as well.

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And you can see that it's got all split via the eight.

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And notice another thing to when it does the split that it actually removes the character from that

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array.

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So in this case, if we're removing the spaces, we don't.

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See any of the spaces, we just see the words, so if you want to find out which character is at index

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value nine, for example, you can see that it's going to return back R because R is in the ninth spot.

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That's the one that's returning are going to comment.

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These treat a string just as you would an array.

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So if you want to get whatever character is at nine, so just as we do character add, we can do that.

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My string nine, just getting it by the index value can also use my string to return a part.

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So we know that R is in the ninth spot and if we take the seven spot, so that should give us the W

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if we want to just return back world, we can extract that from the string using slice where we can

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have a starting position.

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And in this case we did want to start it at seven.

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So refresh and we get the string back starting at the seventh position.

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You can also specify what index value you want to stop the slide.

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So let's try 12 and we refresh.

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So that gives us the ability to pull out the word world out of the string.

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We also have another way to do this or do some similar functionality where we can select substring and

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substring returns, a subset of the string between one index and another or through the end of the string.

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So works the same way as we saw with Slice, where we're taking a substring value, where if we want

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to have a starting position of seven and an ending position of twelve, you can see it returns back

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world as well.

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There's also one more option.

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So there's quite a few options here.

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And this is a shorter format of substring, which returns back characters in the string, beginning

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at a specified location through the number of characters.

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So if we do substring 12, you're going to see that returns back 12 characters.

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So if you want to only return back world, you can use substring seven, starting position seven and

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returning back five characters after that.

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And that returns McWorld.

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So there are slight differences to these and depending on what the situation is, you can use either

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one in order to accomplish what you're trying to find.

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You can also replace content within the string.

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So if we want it to, for instance, outputs and I'm going to create another one where we're just going

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to output these values into the console, because I know we've got quite a lot going on in this console.

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So setting up and I'm going to have a variable called output and we're just going to declare that for

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now.

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And then within the code, we're going to set a value of output and then logout output into the console

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and we'll just output that.

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So that's our current string that we're using right now.

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And if we want it to replace content within the string, we can use the replace method.

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So it looks for a pattern within a string and then does the replacing.

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So this is another really useful one.

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So if you want to look for the word love and change it to enjoy, so maybe you find you don't really

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love JavaScript, you enjoy JavaScript.

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So it will rework the string and it will update those values.

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So you can set it as well to my string if you wanted to.

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So if you could update the current string or you can create a new variable to hold the new value so

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that we can get the first index value and we can also get the last index value, the string object,

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an index of and looking for the index of.

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And in this case, let's do JavaScript, because we do have two of those words in there.

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We can see that the starting position of JavaScript is 13, whereas if we want to do last index of this

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whole return, the last occurrence of the word, so we just put last in front of index of and there

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should be uppercase and refresh and you can see the last index.

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So this JavaScript is starting at position forty seven.

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So you can use these in combination as well, where you can slice at a word if you want, if you know

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it's going to be nine characters and you can get the index starting index value using any one of these

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index of or last index, you can also search within the index.

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So output is going to be equal to my string and search.

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So it executes a search for a pattern between a regular expression and a string object so we can search

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for a particular word.

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In this case, we just use JavaScript together because it makes a lot of sense within this course.

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We're searching and we're getting the same result as we did with index of because it's returning the

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index position of that search result.

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We're going to look at these in more detail as well later on within the section.

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When we look at regular expressions, it don't go anywhere yet with this lesson's not concluded.

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I want you to try out the string methods that we've been showing you within this lesson to turn a string

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into an array of words, replace the content, update the output of the string.

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Have some fun.

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Try out the different string methods that we've covered.