DOM in JavaScript:

 DOM stands for Document Object Model. It is an Application Programming Interface that facilitates the logical layout of content and allows us to create or modify a document. In simple words, one can create/modify/delete contents using DOM.

In the HTML document, DOM views it as a tree of different nodes, where each node is one particular HTML element.

Note: DOM is not a programming language. It is a way to access or modify data.

 

  • How does DOM work?

When a browser reads the HTML document, it creates a representational tree with the nodes along with ways/methods to access different nodes in the tree.

Example of the representational tree:



  • There are majorly four elements in DOM: Documents, elements, text, attributes.
  • DOM provides functions in order to access various DOM elements in the tree. Some commonly used ones are:
    • getElementById(): Access the first element with the specified id.
    • getElementByName(): Accesses all the elements with the specified name
    • getElementByTagName():Accesses all elements with the specified Tag name
    • querySelector(): You can use this method to find elements with one or more CSS selectors.

Comments

Post a Comment

Popular posts from this blog

Day 9: CSS - Font Formate

Image
p1{  font style: italic, } p2{ font-variant: small-caps; } p3{ font-weight: 400px: } p4{ font-size: 12pt } p5{ font-family:  } ----------------------------------------------------------------------------------------------------------------------- The CSS font-family Property : The font-family property in CSS is used to specify the typeface of a text.      If the font name has more than one word, such as "Times New Roman," quotation marks must be used.        Example: The following code applies a font family to a paragraph using class ids:I        Code :   Output :     The CSS font-size Property : The font-size attribute controls a font's size.      It has an impact on the text size of an element. Every element can use it, and its default value is medium. This attribute has values like xx-small, small, x-small, etc.      Font-size can also be specified in pixels (which sets the f...
Read more

else-if condition in if-else statements: Concatenation in JavaScript :

Image
  else-if condition in if-else statements: While specifying conditions for if-else statements, there may arise a need to include more than just two scenarios. For example, suppose we have a variable ‘n’ and we have to check if it is positive or negative. JS code for this problem would look like this: Quite simple, right? However, suppose we twist this problem a bit. If we have to check if the value of ‘n’ is positive, negative, OR zero. Can we do it using only if-else?  No, right? Here comes the scenario where we have to check more than two conditions and give output for each. This is where else-if comes into the game.  Structure of if else-if else looks something like this: If (condition 1)  { statements } else if (condition 2) { statements } else  { statements }   Working for the above code is explained as follows: Condition 1 is checked first. If it is true, statements inside the first block are executed and the remaining conditions are not checked. If t...
Read more

Day 27: Css Variable

Image
 :root {   --main-color: #3498db; } .element {   background-color: var(--main-color); } HTML Code: <!DOCTYPE html> <html lang="en"> <head>   <meta charset="UTF-8">   <meta name="viewport" content="width=device-width, initial-scale=1.0">   <link rel="stylesheet" href="styles.css">   <title>Sample Page</title> </head> <body>   <div class="element">     This is a sample element with the specified background color.   </div> </body> </html> CSS Code: :root {   --main-color: #3498db; } .element {   background-color: var(--main-color);   padding: 20px;   color: white; /* Text color to make it visible on the background */ }
Read more