1. 변수선언
- JS에서는 Python과 다르게 변수선언 방식에 차이점이 있다.
const
- 변수의 재선언, 변수 재할당이 모두 불가능하다.
let
- 변수의 재선언은 불가능하지만, 변수 재할당은 가능하다.
var
- 예전의 방식으로 주로 쓰이지 않는다.
- 변수의 재선언, 변수 재할당이 모두 가능하기 때문에 협업 프로젝트에서 쓰이지 않는다.
2. data type
null
- '아무것도 없다.' = 변수에 값이 없다.
undefined
- 변수는 선언 하였지만 아무것도 정의하지 않았다. = 말 그대로 "아무것도 없다!!"
3. list
- list의 선언은 python과 동일하다.
push()
- python의 append()와 동일
4. object(dict와 비슷한 접근)
const player = {
name: "sa",
age: "20",
skill: "JS",
study:true
}
console.log(player.name)
# sa
console.log(player.age)
# 20
console.log(player.skill)
# JS
console.log(player.study)
# true5. 상태창 띄우기
prompt()
- prompt창을 띄어서 값 받기
alert()
- 경고창 띄우기
6. 연산자
&& - AND연산자
|| - OR연산자
7. 요소를 가지고 오는 방법
getElementById
- document.getElementById()
querySelector
- document.querySelector()
8. Events
classList
- contains() : 클래스가 포함되어있는지 확인
- remove() : 클래스 삭제
- add() : 클래스 추가
- toggle() : 위의 3가지를 한번에 처리해줌(클래스가 있으면 삭제, 클래스가 없으면 추가)
9. time
setInterval 호출방법
- 5초 간격으로 함수 실행
setInterval(sayHello, 5000);
- 5초 간격으로 함수 실행
setTimeout 호출방법
- 5초 뒤에 함수 실행
setTimeout(sayHello, 5000);
- 5초 뒤에 함수 실행
10. 자릿수 채우기
padStart
- 자릿수가 될 때까지 앞쪽에 문자를 넣음 (단, String)
- padStart(자릿수, 문자)
padEnd
- 자릿수가 될 때까지 뒷쪽에 문자를 넣음 (단, String)
- padEnd(자릿수, 문자)
11. JSON 변경
stringify
//data type을 무조건 String형태로 변환해줌.
JSON.stringify([1,2,3,4])
=> "[1,2,3,4]"parse
//String형태를 JS data type으로 변환해줌.
JSON.parse("[1,2,3,4]")
=> [1,2,3,4]12. localStorage
setItem(key,value)
- 저장
getItem(key,value)
- 가져오기
removeItem(key,value)
- 삭제
13. forEach, filter
forEach()
- arr.forEach(function) 를 통해 arr의 모든 요소들을 function할 수 있다.
filter()
- arr.filter(item => item >= 4)을 통해 조건을 주어서 True를 만족하는 값들만 반환한다.
- arr = [1,2,3,4,5,6,7]를 위와 같이 실행하면 [4,5,6,7]이 반환이 된다.
26개의 댓글
I really appreciate this wonderful post that you have provided for us. I assure this would be beneficial for most of the people. 해외선물 솔루션
I can set up my new idea from this post. It gives in depth information. Thanks for this valuable information for all,.. 밤알바 Please continue this great work and I look forward to more of your awesome blog posts. 메랜대리 I can set up my new idea from this post. It gives in depth information. Thanks for this valuable information for all,.. 청주출장마사지 Great things you’ve always shared with us. Just keep writing this kind of posts.The time which was wasted in traveling for tuition now it can be used for studies.Thanks pol88 login I can set up my new idea from this post. It gives in depth information. Thanks for this valuable information for all,.. Take Profit Trader payout rules macau jitu
Thanks a lot pertaining to putting up a real wonderful content! I ran across your web site ideal for our requires. Its content has amazing along with valuable blogposts. Carry on the excellent operate! IPTV UK
I simply believed it might be a concept to publish in case other people had been having issues studying however I'm just a little uncertain basically 'm permitted to place titles as well as handles upon right here. halloween lingerie for women
Thanks for a wonderful share. Your article has proved your hard work and experience you have got in this field. Brilliant .i love it reading. 美國寄件到香港
[I just found this blog and have high hopes for it to continue. Keep up the great work, its hard to find good ones. I have added to my favorites. Thank You.](toto 4d)[[https://techsupport.us.com/](koi toto)[https://www.nonverbal.ch/](olxtoto slot)[https://guidedsys.com/](toto slot)[https://profonia.com/](American Roof Replacement)[https://americanroofchimney.com/](hptoto login)[https://www.stephanie-thornton.com/2012/08/hagia-sophia]
You delivered such an impressive piece to read, giving every subject enlightenment for us to gain information. Thanks for sharing such information with us due to which my several concepts have been cleared.sekabet giriş
Very efficiently written information. It will be beneficial to anybody who utilizes it, including me. Keep up the good work. For sure i will check out more posts. This site seems to get a good amount of visitors. 5ktoto
I am impressed. I don't think Ive met anyone who knows as much about this subject as you do. You are truly well informed and very intelligent. You wrote something that people could understand and made the subject intriguing for everyone. Really, great blog you have got here. Situs Slot
This particular is usually apparently essential and moreover outstanding truth along with for sure fair-minded and moreover admittedly useful My business is looking to find in advance designed for this specific useful stuffs… msg777
Really I enjoy your site with effective and useful information. It is included very nice post with a lot of our resources.thanks for share. i enjoy this post. tulang4d
Really! Everything that a opener it blog post was for my situation. A great deal enjoyed, bookmarked, As i can’t look ahead to alot more! satta matka
Really! Everything that a opener it blog post was for my situation. A great deal enjoyed, bookmarked, As i can’t look ahead to alot more! rajabandot
Document thrilled along with the researching you will designed to makes precise put up impressive. Delightful adventure!prop firm passing service
Dunia maya benar-benar terhambat oleh blog dan forum palsu tanpa prinsip yang kuat, meskipun postingannya tampak brilian dan patut dibaca. Terima kasih banyak telah membagikannya kepada saya. https://mrcrabseafoodclt.com/
May possibly fairly recently up and running an important web log, the data one offer you on this web site contains given a hand to all of us substantially. Bless you designed for your current precious time & get the job done. Rust Hacks
I’m influenced using the surpassing as well as preachy itemizing that you simply provide such small timing. automatic door systems
That is great submit and also i spend time you just read this kind of submit. your blog will be great and you also have got excellent employees within your website. great revealing keep it up.오피스타
The web is actually bogged lower along with phony weblogs without any actual information however the publish had been wonderful as well as really worth the actual study. Thanks with regard to discussing this particular beside me. 카지노 솔루션
Maintain the nice perform, My partner and i examine handful of content with this internet site and also I do believe your net website will be genuine intriguing and contains received sectors regarding great details.Togel china
Fabulous article. That blog post impinges on a whole lot of immediate need conflicts of the contemporary culture. You cannot be uninvolved to help you a lot of these conflicts. It blog post grants ideas and even creative concepts. Highly insightful and even helpful. hptoto
With thanks to get furnishing recently available posts in connection with the dilemma, I actually look ahead to learn extra. pestoto
it is decent not to mention meanful. it is fascinating blog page. Back-links is really effective detail. you possess in fact made it easier many of us what individuals explore blog page and put up these products usefull advice. bandar toto macau
I think this is an informative post and it is very beneficial and knowledgeable. Therefore, I would like to thank you for the endeavors that you have made in writing this article. All the content is absolutely well-researched. Thanks... olxtoto Wow, excellent post. I'd like to draft like this too - taking time and real hard work to make a great article. This post has encouraged me to write some posts that I am going to write soon. Edmonton wedding photographer Thanks for picking out the time to discuss this, I feel great about it and love studying more on this topic. It is extremely helpful for me. Thanks for such a valuable help again. pestoto I got too much interesting stuff on your blog. I guess I am not the only one having all the enjoyment here! Keep up the good work. hptoto
I am impressed. I don't think Ive met anyone who knows as much about this subject as you do. You are truly well informed and very intelligent. You wrote something that people could understand and made the subject intriguing for everyone. Really, great blog you have got here. pestoto
Positive site, where did u come up with the information on this posting?I have read a few of the articles on your website now, and I really like your style. Thanks a million and please keep up the effective work. edctoto
Hello I am so delighted I located your blog, I really located you by mistake, while I was watching on google for something else, Anyways I am here now and could just like to say thank for a tremendous post and a all round entertaining website. Please do keep up the great work. Edmonton wedding photographer
I read that Post and got it fine and informative. Door pulls