JavaScript supports a compact set of statements, specifically control flow statements, that you can use to incorporate a great deal of interactivity in your application. This chapter provides an overview of these statements.

A named backreference refers to the submatch of a previous named capturing group and matches the same text as that group. For unnamed capturing groups, you need to use the normal backreference syntax.

Perhaps more exciting than just fills and strokes is the fact that you can also create and apply gradients as either fills or strokes.

Now we're ready to start distorting our beautiful images. But first, let's formally introduce the <g> element. With this helper, you can assign properties to a complete set of elements. Actually, that's its only purpose.

The conditional (ternary) operator is the only JavaScript operator that takes three operands: a condition followed by a question mark (?), then an expression to execute if the condition is truthy followed by a colon (:), and finally the expression to execute if the condition is falsy. This operator is frequently used as an alternative to an if...else statement.

The <switch> SVG element evaluates any requiredFeatures, requiredExtensions and systemLanguage attributes on its direct child elements in order, and then renders the first child where these attributes evaluate to true.

The InternalError object indicates an error that occurred internally in the JavaScript engine.

The <feDisplacementMap> SVG filter primitive uses the pixel values from the image from in2 to spatially displace the image from in.

Erasing part of what you have created might seem contradictory at first. But when you, for example, try to create a semicircle in SVG, you will find out the use of the following properties quickly:

The <feMorphology> SVG filter primitive is used to erode or dilate the input image. Its usefulness lies especially in fattening or thinning effects.