Objective: To learn how CSS selectors work in detail. Previous Overview: Building blocks Next. Complete beginners start here! Getting started with the Web Getting started with the Web overview Installing basic software What will your website look like?
A first splash into JavaScript What went wrong? Type selectors. The universal selector. Class selectors. ID selectors. Attribute selectors. To put it another way, this CSS selector will match any element on your page if it has a certain attribute. An attribute is content added to the opening tag of a HTML element. It can be things like id , name or value. There are seven attribute selectors that each allow you to find elements based on whether an attribute is present and what the value may contain.
The common syntax for these selectors is the selector followed by [ ] square brackets in which you state what you are looking for. The selector could be anything like a class selector or even a universal selector. Today we are going to look at the five most common attribute selectors. In order to understand these five attribute selectors, let's look at each of them with examples. In the example above, our present selector will find any a element that has a title attribute and apply the style definition to them.
All other a elements that don't have a title attribute will not be styled as per above. This attribute selector finds an element with an exact match attribute value. This attribute selector finds any element that begins with a value you specify. In the example above the begins with selector finds any a element that has an href attribute and that begins with "https".
Much like the begin with selector, this attribute selector does the opposite and finds any element that ends with a value you specify. This is one I actually use for my website. This attribute selector finds any element that contains the value you are looking for somewhere in the attributes value. This means that the value must contain at least one occurrence of the value.
In the above example the contains attribute selector finds any a element that has an href that contains the value "peterlunch". The next advanced CSS selectors are combination selectors.
These selectors can combine more than one CSS selector. There are four types of combination selectors in CSS:. To understand how these selectors work, you must first understand that HTML follows a family tree hierarchy. This means that there is a parent element which can contain children, and the children can have children, and so on and so forth like a family tree.
In the example above, the div is the parent, its children are the article elements, and the articles are parents to the h1 and p children. With that knowledge front of mind, let's explore each of these combination selectors one by one with examples to understand how they work. The descendant combination selector matches all elements that are descendants of a specified element.
The child combination selector matches all elements that are children of a specific element. This is different to the descendant combination selector, as it only selects direct children of the parent element. Referring to our HTML hierarchy example above, this selector will only find the first p tag and not the p tags within the article tags.
It does this as they are not direct children of the parent div element. A good real world example of this is having the text that immediately follows an image to be styled like a caption. In the example above, any p element that follows an image will be styled with the above definition. The general sibling selector selects any elements that are siblings of an element.
Navbar Vertical Navbar Horizontal Navbar. Shadow Effects Box Shadow. Note: An id name cannot start with a number! Note: A class name cannot start with a number! Report Error. Will still parse correctly and match :valid even in browsers which don't support :unsupported , whereas:. Will be ignored in browsers which don't support :unsupported even if they support :valid. The :is pseudo-class can greatly simplify your CSS selectors. For example, the following CSS:.
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