interpolation in angular

Interpolation in angular is a technique used to dynamically generate content based on data or variables. It is a way of injecting data into templates using a special syntax. 

In Angular, interpolation is achieved by wrapping a variable or expression 

in double curly braces {{ }}.

For example:

If you have a variable name defined in your component, you can display its value in the template using interpolation as follows:

<p>Hello, {{name}}!</p>

If the value of the name is "zaheer", the above code will render as:

<p>Hello, John!</p>

Angular supports expressions inside the double curly braces as well. This means you can perform arithmetic operations or call functions and display their results in the template using interpolation. For example:

Interpolation is a powerful feature of Angular that makes it easy to create dynamic and responsive applications.

Examples of how interpolation can be used in Angular:

Displaying Component Properties:

One common use case for interpolation is to display component properties in the template. 

Let's say we have a component with a property called message. 

We can use interpolation to display the value of the message in the template like this:

<p>{{ message }}</p>

Performing String Concatenation:

Interpolation can also be used to concatenate strings in the template. For example, 

let's say we have two properties in our component, firstName, and lastName. 

We can use interpolation to combine these two properties into a single string in the template like this:

<p>{{ firstName + ' ' + lastName }}</p>

Evaluating Expressions:

In addition to displaying properties and concatenating strings, interpolation can also be used to evaluate expressions in the template. 

For example:

Let's say we have a component with a property called count. 

We can use interpolation to display the result of an expression that doubles the value of the count like this:

<p>{{ count * 2 }}</p>

Conditionally Displaying Content:

Interpolation can also be used to conditionally display content in the template using the ternary operator. For example, let's say we have a component with a property called isLoggedIn. We can use interpolation to display a different message depending on whether the user is logged in or not like this:

<p>{{ isLoggedIn ? 'Welcome back!' : 
'Please log in.' }}</p>

Using Template Variables:

In addition to displaying component properties and evaluating expressions, interpolation can also be used with template variables. Template variables allow you to reference elements in your template and perform actions on them. 

For example:

Let's say we have an input element in our template and we want to reference its value in our component. We can use a template variable to achieve this:

<input #myInput type="text">

<p>{{ myInput.value }}</p>

In the above example, we've created a template variable called myInput that references the input element. We can then use interpolation to display the value of the input element's value property in the template.

Displaying Arrays:

Interpolation can also be used to display arrays in the template. Let's say we have an array of numbers in our component. 

We can use interpolation to display each number in the array using the *ngFor directive:

<ul> <li *ngFor="let number of numbers">

{{ number }}</li>

</ul>

In the above example, we're using the *ngFor directive to loop over the numbers array and 

display each number in a list item using interpolation.

Using Pipes:

You can use pipes with interpolation to format and transform data before displaying it in the template. For example: 

Let's say we have a component with a property called price that contains a number. We can use the currency pipe to format the price as a currency value in the template like this:

<p>{{ price | currency }}</p>

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How to add all the files except one file into the git

To add all files in a git repository except for one file, you can use the following command:

git add --all :!file_to_exclude

Replace  "file_to_exclude"  with the name of the file that you want to exclude from the list of files to be added.

For example:

If you want to add all files except for a file named  "secret.txt",  you can use the following command:

git add --all :!secret.txt

This will add all files in the repository except for the "secret.txt" file.

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Html complete Notes

posts

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css syntax and selectors

CSS (Cascading Style Sheets) is a language used for describing the presentation of a document written in a markup language, such as HTML or XML. 

It is used to control the layout and visual design of web pages.

CSS selectors are used to select elements on a web page and apply styles to them. 

Some common types of selectors include:

Element selectors: Selects elements based on their HTML tag name, such as "p" for paragraphs or "h1" for headings.

Example:

p {
color: blue;
}

Class selectors: Selects elements based on their class attribute. Classes are assigned to elements using the "class" attribute, and multiple elements can share the same class. 

Example:

.highlight {
    background-color: yellow;
 }

 

ID selectors: Selects elements based on their id attribute. 

IDs are assigned to elements using the "id" attribute, and each element can have only one unique id. 

Example:

 #header {
       font-size: 20px;
   }

 

  

Attribute selectors: Selects elements based on their attributes and attribute values. 

Example:

a[href='https://example.com']
     {
       color: red;
     }

    

There are also more advanced selectors such as:

Pseudo-class selectors: Selects elements based on their state or position in the document, such as links that have been visited or elements that are being hovered over. 

Example: 

  a:hover {
       text-decoration: underline;
   }

 

Pseudo-element selectors: Selects a specific part of an element, such as the first letter of a paragraph or the ::before and ::after of an element. 

Example:

  p::first-letter {
     font-size: 20px;
  }

You can also group selectors to apply the same styles to multiple elements. 

Example:

h1, h2, h3 {
  color: blue;
  text-align: center;
}

You can also use CSS cascading and inheritance to apply styles to child elements. 

Example:

#parent {
color: blue;
}
#parent .child {
background-color: yellow;
}

It is important to note that the specificity of the selectors is also important, more specific selectors will have precedence over more general selectors.

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complete HTML course

index:

1. Introduction to html
2. Basic html tags
3. How to create or edit html file
4. About html elements
5. Empty elements in html you must know
6. Html attributes in detailed
7. Comments in html
8. Html styles in detailed
9. Html colors and its types
10. Html responsive and media queries to make responsive website
11. Html headings
12. Block elements and inline elements
13. Links or hyperlinks in HTML
14. HTML text formatting
15. Sections and semantics in HTML
16. div and span in HTML
17. Images in HTML
18. Filepaths in HTML
19. Tables in HTML
20. Lists in HTML
21. HTML forms
22. HTML inputs
23. Dropdown list
24. SEO with HTML meta
25. HTML audios
26. HTML videos
27. IFRAME in HTML
28. HTML youtube videos
29. Useful HTML character entities
30. HTML pre elements
31. HTML figures

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html figures

Html figures and their attributes

HTML figures are used to embed images, videos, or other types of media within an HTML document. They are typically used to include illustrations, diagrams, or photographs that are related to the content of the document.

The <figure> tag is used to define a container for the media, and the <img> tag is used to define the actual media element.

Attributes of the <figure> tag include:

class: specifies a class name for the element

id: specifies a unique id for the element

style: specifies an inline CSS style for the element

title: provides additional information about the element

Attributes of the <img> tag include:

src: specifies the URL of the image

alt: provides alternative text for the image in case the image cannot be displayed

width and height: specify the dimensions of the image

style: specifies an inline CSS style for the element

title: provides additional information about the element

Here is an example of using the <figure> and <img> tags to embed an image in an HTML document:

<figure>
<img src="image.jpg"
alt="image" 
width="300" height=
"200">
<figcaption>my image
</figcaption>
</figure>

In this example, the <img> tag is used to define the image element and the src attribute is used to specify the URL of the image. The alt attribute provides alternative text for the image, and the width and height attributes specify the dimensions of the image. The <figcaption> is used to provide a caption for the image

Note that the <figcaption> is optional and can be used to provide a caption for the image.

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html pre element

The HTML <pre> element is used to define preformatted text. Text within an <pre> element is displayed in a fixed-width font, and whitespace characters such as spaces and line breaks are honored. 

This allows the text to maintain its original formattings, such as multiple spaces or line breaks.

The <pre> element is often used to display code snippets or other text that should retain its original formatting.

Example:

<pre>
This is a preformatted
text block.
White space is preserved.
</pre>

It also has a default CSS styling, it has a monospace font, a white background, and the text is wrapped.

You can also use the white-space property to control how the text is displayed, such as using white-space: pre-line; to wrap text but still honor line breaks.

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