Javascript show html code

2 Ways To Add HTML Code In Javascript (A Quick Guide)

Welcome to a short beginner’s tutorial on how to add HTML code in Javascript. So you have finally gotten to the point of working with both HTML and Javascript, but the challenge is that you now have to add some HTML to an existing page.

Adding HTML code using Javascript is actually a simple “get target container and insert HTML” process:

1. By directly changing or appending to the inner HTML.
   • var target = document.getElementById(«ID»);
   • target.innerHTML + ;
2. By creating and inserting a new element.
   • var newElement = document.createElement(«p»);
   • newElement.innerHTML = «CONTENTS»;
   • document.getElementById(«ID»).appendChild(newElement);

Yep. As simple as this select-insert mechanism may seem like, there are actually quite a few ways to select and insert elements. So let us walk through some actual examples in this tutorial – Read on!

TLDR – QUICK SLIDES

TABLE OF CONTENTS

WAYS TO ADD HTML CODE

All right, let us now move into the actual examples themselves – How we can work with Javascript to add HTML code and elements.

METHOD 1) DIRECTLY CHANGE HTML CODE

• (A) First, we give the HTML element a unique id .
• (B) Then select it with var ELEMENT = document.getElementById(ID) in Javascript.
• (C & D) Finally, take note that innerHTML can be used in two directions.
  • var CONTENTS = ELEMENT.innerHTML to get the current contents.
  • ELEMENT.innerHTML = «FOO!» to replace the contents.
  • ELEMENT.innerHTML += «FOO!» to append to the existing contents.

  METHOD 2) CREATE & APPEND HTML ELEMENTS

  • (A & B) As usual, give the HTML element an id . Then use var PARENT = document.getElementById(«ID») to get it.
  • (C) But instead of directly replacing the innerHTML , we create a new HTML element instead.
    • We use var ELEMENT = document.createElement(«TAG») to create a new HTML tag.
    • Then change the contents using ELEMENT.innerHTML = «FOO» … Which you already know.
    • Finally, append the new element to the parent – PARENT.appendChild(ELEMENT) .

    MORE HTML SELECTION & INSERTION

    So far so good? Here are a few more examples of the various ways to select and insert HTML elements.

    GET HTML ELEMENTS IN JAVASCRIPT

      
      DemoD 
    not John Wick.
     // (B) GET BY ID var demoA = document.getElementById("demoA"); console.log(demoA); // 
    ] // (D) GET BY CSS CLASS var demoC = document.getElementsByClassName("demoC"); console.log(demoC); // html collection - [demoD] // (F) GET BY QUERY SELECTOR var demoE = document.querySelector("#demoE strong"); console.log(demoE); // not // (G) GET BY QUERY SELECTOR (MULTIPLE SELECTORS) var demoF = document.querySelectorAll("span.demoC, p#demoE"); console.log(demoF); // node list - [ 

    SET HTML/CSS PROPERTIES

      window.addEventListener("load", () => < // (A) GET HTML LIST var ul = document.getElementById("thelist"); // (B) DATA var data = ["Foo", "Bar", "Hello", "World", "John", "Doe"]; // (C) ADD LIST ITEMS for (let idx in data) < let li = document.createElement("li"); li.innerHTML = data[idx]; li.id = "item-" + idx; // set id li.style.color = "red"; // set style li.classList.add("dummy"); // add css class ul.appendChild(li); >>); 

    TAKE EXTRA NOTE OF THE LOADING ORDER!

    Lastly, this is a common pitfall among beginners – Not taking note of the order in which things are being loaded. Notice how demo is NULL in this example? Isn’t already defined!? Nope, Javascript is not broken. What happened is that HTML files load in a top-to-bottom, left-to-right manner.

    The is loaded first, and ran before is even rendered – This is how getElementById("demo") ends up as a NULL . To solve this problem, we can use window.addEventListener("load") (as in the previous example) to wait for the window to be fully loaded before proceeding with the scripts.

    DOWNLOAD & NOTES

    Here is the download link to the example code, so you don’t have to copy-paste everything.

    SUPPORT

    600+ free tutorials & projects on Code Boxx and still growing. I insist on not turning Code Boxx into a "paid scripts and courses" business, so every little bit of support helps.

    EXAMPLE CODE DOWNLOAD

    Click here for the source code on GitHub gist, just click on “download zip” or do a git clone. I have released it under the MIT license, so feel free to build on top of it or use it in your own project.

    EXTRA BITS & LINKS

    That’s all for this guide, and here is a small section on some extras and links that may be useful to you.

    DIRECT HTML MANIPULATION VS CREATING OBJECTS

    • innerHTML works better when you are dealing with changing the text contents inside a single element.
    • createElement() makes more sense when you are dealing with lists and tables.

    So yep – It is up to you to decide which is more comfortable.

    RECOMMENDED READS

    TUTORIAL VIDEO

    INFOGRAPHIC CHEAT SHEET

    

    THE END

    Thank you for reading, and we have come to the end of this guide. I hope that it has helped you with your project, and if you want to share anything with this guide, please feel free to comment below. Good luck and happy coding!

    Leave a Comment Cancel Reply

    Search

    Breakthrough Javascript

    

    Take pictures with the webcam, voice commands, video calls, GPS, NFC. Yes, all possible with Javascript - Check out Breakthrough Javascript!

    Socials

    About Me

    

    W.S. Toh is a senior web developer and SEO practitioner with over 20 years of experience. Graduated from the University of London. When not secretly being an evil tech ninja, he enjoys photography and working on DIY projects.

    Code Boxx participates in the eBay Partner Network, an affiliate program designed for sites to earn commission fees by linking to ebay.com. We also participate in affiliate programs with Bluehost, ShareASale, Clickbank, and other sites. We are compensated for referring traffic.

    Источник

    JavaScript Output

    To access an HTML element, JavaScript can use the document.getElementById(id) method.

    The id attribute defines the HTML element. The innerHTML property defines the HTML content:

    Example

    My First Web Page

    My First Paragraph

    document.getElementById("demo").innerHTML = 5 + 6;
    

    Changing the innerHTML property of an HTML element is a common way to display data in HTML.

    Using document.write()

    For testing purposes, it is convenient to use document.write() :

    Example

    My First Web Page

    My first paragraph.

    Using document.write() after an HTML document is loaded, will delete all existing HTML:

    Example

    My First Web Page

    My first paragraph.

    The document.write() method should only be used for testing.

    Using window.alert()

    You can use an alert box to display data:

    Example

    My First Web Page

    My first paragraph.

    You can skip the window keyword.

    In JavaScript, the window object is the global scope object. This means that variables, properties, and methods by default belong to the window object. This also means that specifying the window keyword is optional:

    Example

    My First Web Page

    My first paragraph.

    Using console.log()

    For debugging purposes, you can call the console.log() method in the browser to display data.

    You will learn more about debugging in a later chapter.

    Example

    JavaScript Print

    JavaScript does not have any print object or print methods.

    You cannot access output devices from JavaScript.

    The only exception is that you can call the window.print() method in the browser to print the content of the current window.

    Example

    

    COLOR PICKER

    

    

    Report Error

    If you want to report an error, or if you want to make a suggestion, do not hesitate to send us an e-mail:

    Thank You For Helping Us!

    Your message has been sent to W3Schools.

    Top Tutorials

    Top References

    Top Examples

    Get Certified

    W3Schools is optimized for learning and training. Examples might be simplified to improve reading and learning. Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content. While using W3Schools, you agree to have read and accepted our terms of use, cookie and privacy policy.

    Источник

    Как выводить html с помощью JavaScript

    С помощью JavaScript удобно делать "мини" движки для сайтов сделанных на html. Например, можно выводить через яваскрипт левый сайдбар, шапку и футер сайта, поскольку эти элементы часто изменяются. Ниже я расскажу о том, как это делается. Помимо этого способа, есть ещё один отличный способ вывода контента на сайте: вывод html с помощью ajax.

    Для вывода html с помощью JavaScript нужно сделать:
    1. Создать файл с расширением .js . Например, topjava.js .

    2. Напишите в этом файле следующее:

    document.write('Сюда можно писать html код'); document.write('
    '); document.write('Как не писать каждый раз документ райт?'); document.write('
    '); document.write('Очень просто'); document.write('Это первая строка'+ 'Это втора строка'+ 'Видите? Можно писать и так'); document.write('
    '); document.write('Стоит так же сказать, что вместо одинарной'+ ' ковычки можно использовать "'); document.write('
    '); document.write("Например так"); document.write('Если Вам надо написать одинарную ковычку, то'+ ' напишите её через слэш: \' - так '+ 'она будет воспринята как текст');

    Если Вы будете писать текст без пробелов, то использование переносов '+ на следующие строки не обязательны. С текстом можно писать любой html код.

    Если Вам нужно подключить файл JavaScript, то его можно подключить так:

    3. В месте где Вы хотите вывести текст из javascript напишите следующие:

    Если ничего не выводится, то это означает, что у Вас ошибка в файле topjava.js . Скорее всего, где-то пропущена кавычка.

    Таким образом, Вы можете написать несколько яваскриптов и выводить различные элементы сайта. Это очень удобно, когда сайт написан на html и на нем много страниц. Вы изменяете код всего лишь в одном файлике, а получается, что он изменяется на всем сайте.

    Источник

    JavaScript Introduction

    This page contains some examples of what JavaScript can do.

    JavaScript Can Change HTML Content

    One of many JavaScript HTML methods is getElementById() .

    The example below "finds" an HTML element (with and changes the element content (innerHTML) to "Hello JavaScript":

    Example

    JavaScript accepts both double and single quotes:

    Example

    JavaScript Can Change HTML Attribute Values

    In this example JavaScript changes the value of the src (source) attribute of an tag:

    The Light Bulb

    JavaScript Can Change HTML Styles (CSS)

    Changing the style of an HTML element, is a variant of changing an HTML attribute:

    Example

    JavaScript Can Hide HTML Elements

    Hiding HTML elements can be done by changing the display style:

    Example

    JavaScript Can Show HTML Elements

    Showing hidden HTML elements can also be done by changing the display style:

    Example

    Did You Know?

    JavaScript and Java are completely different languages, both in concept and design.

    JavaScript was invented by Brendan Eich in 1995, and became an ECMA standard in 1997.

    ECMA-262 is the official name of the standard. ECMAScript is the official name of the language.

    

    COLOR PICKER

    

    

    Report Error

    If you want to report an error, or if you want to make a suggestion, do not hesitate to send us an e-mail:

    Thank You For Helping Us!

    Your message has been sent to W3Schools.

    Top Tutorials

    Top References

    Top Examples

    Get Certified

    W3Schools is optimized for learning and training. Examples might be simplified to improve reading and learning. Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content. While using W3Schools, you agree to have read and accepted our terms of use, cookie and privacy policy.

    Источник

    Javascript show html code

    

    WordPress 6 с Нуля до Гуру

    Этот курс научит Вас созданию самых разных сайтов на самой популярной в мире CMS - WordPress. Вы увидите установку и настройку локального сервера, разбор каждой настройки, каждой кнопки и каждого пункта меню в панели WordPress.

    Также Вы получите и всю практику, поскольку прямо в курсе с нуля создаётся полноценный Интернет-магазин, который затем публикуется в Интернете. И всё это прямо на Ваших глазах.

    Помимо уроков к курсу идут упражнения для закрепления материала.

    И, наконец, к курсу идёт ценнейший Бонус по тому, как используя ChatGPT и создавая контент для сайта, можно выйти на пассивный доход. Вы наглядно увидите, как зарегистрироваться в ChatGPT (в том числе, и если Вы из России), как правильно выбрать тему для сайта, как правильно генерировать статьи для него(чтобы они индексировались поисковыми системами) и как правильно монетизировать трафик на сайте.

    Подпишитесь на мой канал на YouTube, где я регулярно публикую новые видео.

    

    Подписаться

    

    Подписавшись по E-mail, Вы будете получать уведомления о новых статьях.

    

    Подписаться

    

    Добавляйтесь ко мне в друзья ВКонтакте! Отзывы о сайте и обо мне оставляйте в моей группе.

    

    Мой аккаунт Моя группа

    Источник