1 00:00:00,630 --> 00:00:06,360 Welcome back in this unit I'm going to introduce a new tool called Jay queery And before we get writing 2 00:00:06,360 --> 00:00:12,990 Jay Corey I'm going to take a little bit to talk about conceptually what it is and then talk about why 3 00:00:12,990 --> 00:00:17,790 you would use a query and why you might not use it and give you a little bit of my own opinion on that 4 00:00:17,790 --> 00:00:18,710 debate. 5 00:00:19,260 --> 00:00:21,050 OK let's get started. 6 00:00:21,840 --> 00:00:25,990 So what is Jay query if you've done any research on your own. 7 00:00:26,040 --> 00:00:31,040 If you've been taking any classes online or reading books you've probably encountered the term before 8 00:00:31,350 --> 00:00:36,330 and you may have learned a little bit of it as well and that's because it is the most popular tool out 9 00:00:36,330 --> 00:00:37,600 there for javascript. 10 00:00:37,680 --> 00:00:40,600 It's the most popular javascript library period. 11 00:00:41,040 --> 00:00:43,900 And what it does is it helps us manipulate the DOM. 12 00:00:44,190 --> 00:00:48,290 So I have the J query docs open here the official homepage. 13 00:00:48,450 --> 00:00:55,960 J Querrey dot com and I'm just going to read briefly this paragraph right here so it tells us queery 14 00:00:56,040 --> 00:01:02,880 is a fast small and feature rich javascript library and makes things like H.T. mail document traversal 15 00:01:03,120 --> 00:01:07,080 and manipulation event handling animation and Ajax. 16 00:01:07,080 --> 00:01:13,650 Much simpler with an easy use API that works across a multitude of browsers with a combination of versatility 17 00:01:13,920 --> 00:01:15,270 and extensibility. 18 00:01:15,390 --> 00:01:19,140 Jay Querrey has changed the way that millions of people write javascript. 19 00:01:19,230 --> 00:01:24,600 To sum that up Jay query is a javascript library that makes our lives easier. 20 00:01:24,630 --> 00:01:30,030 It helps us do things like selecting elements and manipulating elements changing styles adding event 21 00:01:30,030 --> 00:01:34,840 handlers animating things and Ajax which we'll talk about in another unit. 22 00:01:35,310 --> 00:01:40,290 So the point of J query is that it helps us do things faster and it makes it easier to do those things 23 00:01:40,290 --> 00:01:41,580 . 24 00:01:41,580 --> 00:01:45,030 Now let's talk about the term javascript library. 25 00:01:45,030 --> 00:01:50,130 So this says here that J query is a fast small and feature rich javascript library. 26 00:01:50,310 --> 00:01:52,290 So what is a library. 27 00:01:52,290 --> 00:01:57,450 The concept of a library in javascript is actually one that exists in other programming languages as 28 00:01:57,450 --> 00:01:58,200 well. 29 00:01:58,200 --> 00:02:03,810 The core idea is that we can take code that someone else wrote and we can add it to our own project 30 00:02:03,900 --> 00:02:05,700 and use it instead of her own code. 31 00:02:06,120 --> 00:02:06,870 So that's all that J. 32 00:02:06,870 --> 00:02:07,620 Korea's. 33 00:02:07,770 --> 00:02:13,920 It's a single file that someone else wrote a team wrote now with a bunch of methods and properties inside 34 00:02:13,920 --> 00:02:19,380 of it and then we just add it to our own project so that we can use all of those methods and I'll show 35 00:02:19,380 --> 00:02:21,230 you on the API docs here. 36 00:02:21,450 --> 00:02:24,700 J worry comes with a ton of methods and you can see over here. 37 00:02:24,870 --> 00:02:27,590 Let's click on one of these categories see SS. 38 00:02:27,780 --> 00:02:32,860 And these are all the methods that J Querrey comes with that have to do with C Ss. 39 00:02:33,090 --> 00:02:36,830 We'll talk about how we include J query and just a little bit. 40 00:02:37,830 --> 00:02:42,900 Again it helps us with things like selecting and manipulating elements creating elements adding event 41 00:02:42,900 --> 00:02:48,250 listeners animating adding effects and then this last thing AJAX which we haven't talked about yet.