Flash cards
Review the key moves
What is the main idea behind CSS Counters?
Lesson checks
Practice each idea before moving on
Short Mimo-style checks built from this lesson's code, terms, and sequence.
Which statement best captures the main point of this lesson?
Complete the missing token from the example code.
___-reset: section;Put the learning moves in the order that makes the concept easiest to apply.
With CSS counters, you can create dynamic numbering of elements (like headings, sections, or list items) without using JavaScript.
CSS counters are "variables" maintained by CSS, and their values can be incremented (or decremented) by CSS rules.
CSS Automatic Numbering With Counters
CSS counters are like "variables". The variable values can be incremented (or decremented) by CSS rules.
To work with CSS counters we will use the following properties:
- counter-reset - Creates or resets a counter
- counter-increment - Increments or decrements a counter
- content - Inserts generated content
- counter() - Adds the value of a counter to an element
To use a CSS counter, it must first be created with the counter-reset property.
CSS Increase and Decrease Counter
The following example creates a counter for the page (in the body selector), then it increments the counter value by 1 for each <h2> element:
Example
body {
counter-reset: section;
}
h2::before {
counter-increment: section;
content: "Section " counter(section) ": ";
}Live preview
Decrementing a Counter
The counter-increment property has a second parameter. The default value is 1. To decrease the counter value, you can set it to -1.
Example
body {
counter-reset: section;
}
h2::before {
counter-increment: section
-1;
content: "Section " counter(section) ": ";
}Live preview
Incrementing by Custom Values
You can increment the counter by any value. Here we increment by 2:
Example
body {
counter-reset: section;
}
h2::before {
counter-increment: section
2;
content: "Section " counter(section) ": ";
}Live preview