The mathematical attribute indicates the alignment coordinate for glyphs to achieve mathematical baseline alignment for horizontally oriented glyph layouts. The value is an offset in the font coordinate system.

The constructor method is a special method of a class for creating and initializing an object instance of that class.

The v-mathematical attribute indicates the alignment coordinate for glyphs to achieve mathematical baseline alignment for vertically oriented glyph layouts. The value is an offset in the font coordinate system relative to the glyph-specific vert-origin-x attribute.

The stroke-dashoffset attribute is a presentation attribute defining an offset on the rendering of the associated dash array.

Below, you'll find a list of errors which are thrown by JavaScript. These errors can be a helpful debugging aid, but the reported problem isn't always immediately clear. The pages below will provide additional details about these errors. Each error is an object based upon the Error object, and has a name and a message.

The logical OR (||) operator (logical disjunction) for a set of operands is true if and only if one or more of its operands is true. It is typically used with boolean (logical) values. When it is, it returns a Boolean value. However, the || operator actually returns the value of one of the specified operands, so if this operator is used with non-Boolean values, it will return a non-Boolean value.

The elevation attribute specifies the direction angle for the light source from the XY plane towards the Z-axis, in degrees. Note that the positive Z-axis points towards the viewer of the content.

The new operator lets developers create an instance of a user-defined object type or of one of the built-in object types that has a constructor function.

Property accessors provide access to an object's properties by using the dot notation or the bracket notation.

The overline-thickness attribute represents the ideal thickness of the overline. The overline thickness is expressed in the font's coordinate system.