Topic: HTML

Explains what HTML is and how to use it for web development.

Image Tag

Unlike most elements, the image tag is a specific reference in your HTML document to an image on your website. It is more like an advanced link to an image file. The HTML image tag actually retrieves the image and displays it in your web page. However, unlike most elements, the image tag requires an attribute in order to display an image. The opening and closing tags are a unique case in the sense that they are combined, <img />. The primary attribute of the img tag is src=””, where you would put the link to the image in between the quotation marks. Of course, the image tag has many other attributes, but this is the most important one you need to know to get started.

Show an Image

Example
<img src="/images/smiley2.jpg" width="200"/>
Result

Pretty cool huh? Now, you might be wondering what is this width=”200″. The width and height are both attributes of the HTML image tag. I try to only use one or the other as this permits the browser to resize the image correctly. If you used them both at the same time and they are not the proper dimensions, it will stretch or shrink the image. The src is the attribute we set to the link to our image, /images/smiley2.jpg

Important Alt attribute

The second most important attribute for an image is called the alt attribute. The alt attribute is only activated when an image fails to load. If you ever remove or lose an image from your website, the alt attribute will step up and display its value to the browser. Additionally, search engines cannot read what an image is all about, so search engines use the HTML image alt attribute to “understand” it. In conclusion, always set the alt attribute and set it to a value that tells the user about the image.

Example
<img src="/images/smiley2.jpg" alt="A smiley face I created" width="200"/>

References

Table Tag

The HTML table tag has done wonders for the internet as a whole. However, tables are often used as grids or containers, which is not the appropriate use of HTML tables. Tables are not very flexible and are primarily intended to show tabular data. The tags of a table require more opening and closing tags than the average HTML element. Let’s look at an example to see:

Example
<table>
    <tr>
        <td>Row 1 Column 1</td>
        <td>Row 1 Column 2</td>
    </tr>
    <tr>
        <td>Row 2 Column 1</td> 
        <td>Row 2 Column 2</td>
    </tr>
</table>
Result
Row 1 Column 1Row 1 Column 2
Row 2 Column 1Row 2 Column 2

Three separate tags are involved in creating an HTML table, <table>, <tr>, and<td>. The <table> is simply the encasing of a table. To identify a new row, which must come first, you should use the <tr> tag. Inside of the table row tag, you can specify columns by using the <td> tag. Remember that you can access all of the accepted HTML attributes of every element by clicking the w3.org reference in the HTML Attributes references.

It’s worth mentioning that you must structure the table and table tags properly. All tr must be opened and closed inside the <table></table> tags. The th and td tags must be opened and closed inside the tr tags. If you do this incorrectly, you will have one messed up looking table.

Table Headers

Sometimes when creating an HTML table, you might want the top row to stand out from the rest as a heading. All you need to do is replace the HTML table column tag, <td>, with a table header tag, <th>. It is entirely possible to use these multiple times different rows to have multiple “sections” in your table. Table headers also permit you to have better control of your CSS.

Example
<table>
    <tr>
        <th>Row 1 Column 1</th>
        <th>Row 1 Column 2</th> 
    </tr>
    <tr>
        <td>Row 2 Column 1</td> 
        <td>Row 2 Column 2</td> 
    </tr>
</table>

Merging Columns

Sometimes, you might want to merge two columns to display your data correctly in a row. All we need to do is use the colspan attribute of the HTML table. Let’s merge two columns in one row.

Example
<table>
    <tr>
        <td colspan="2">Row 1 Column 1</td>
    </tr>
    <tr>
        <td>Row 2 Column 1</td> 
        <td>Row 2 Column 2</td>
    </tr>
</table>
Result
Row 1 Column 1
Row 2 Column 1Row 2 Column 2

References

List Tags

When writing any document, lists provide quick bursts of information in the most efficient manner. HTML Lists are no different when used in an HTML document. In a browser, there are only two types of lists, ordered and unordered. Ordered lists obviously have a predictable layout such as numbers or roman numerals. The standard for ordered lists is numbers, but you can always modify that in the CSS. Unordered lists are generally small black dots that can also be changed in the CSS. Lists require two sets of tags. The encapsulating tag is <ol> for ordered lists and <ul> for unordered lists. The element inside that tag is the <li> where your content will go in between the opening and closing tags of the that li element.

HTML Ordered Lists

Example
<ol>
    <li>List Item 1</li>
    <li>List Item 2</li>
</ol>
Result
  1. List Item 1
  2. List Item 2

HTML Unordered Lists

Example
<ul>
    <li>List Item 1</li>
    <li>List Item 2</li>
</ul>
Result
  • List Item 1
  • List Item 2

Pretty easy to understand there, but what if we wanted to have another level in the list? You can create lists inside lists. You would simply just start putting <ul> with internal <li> inside the previous <li> elements. Alright, maybe that is somewhat complicated… example please!

HTML Multiple Level Lists

Example
<ul>
    <li>List Item 1 
        <ul>
            <li>List Item 1 Sub 1</li> 
            <li>List Item 1 Sub 2</li>
        </ul>
    </li>
</ul>
Result
  • List Item 1
    • List Item 1 Sub 1
    • List Item 1 Sub 2

References

Div and Span Tags

Div tags and span tags are very common HTML elements that are growing in popularity due to their flexibility. HTML div tags are more specific for organizational tasks like setting up the layout of your page, which are preferred over tables because of their fluid like nature. Span tags are used more to permit customization of text and are often used inside other HTML elements to customize a certain piece of content from the rest. For instance, if you see my green text that refers to code, it is a span tag. The internal layout of this page is created with div elements.

HTML Div Element

The div element is a block level element, much like the paragraph tag. However, like I mentioned above, the div is more for creating internal structures in your document. Let’s see what in the heck I am talking about.

Example
<div> I am a div!</div> 
<div> Me too!</div>
Result
I am a div!
Me too!

HTML Span Element

The HTML span element is an inline element, which means that it can be used inside a block element and not create a new line. If you ever want to highlight some text inside a paragraph, wrap that text in a span tag and give it a class. Span tags are often used to incorporate a specific CSS style to differentiate certain parts of content.

Example
<p> Something here is <span style="color:#900;"> special</span> , but which one?</p>
Result

Something here is special, but which one?

The span tag is inside the paragraph tags, and I added the style attribute to the span element that tells the browser to show the text as red. Remember it is not ideal to embed styles inside the body, but it illustrates my point. Instead, I would typically create a class for a specific purpose, but we will get to that in the CSS tutorials.

References