The let declaration declares re-assignable, block-scoped local variables, optionally initializing each to a value.

The const declaration declares block-scoped local variables. The value of a constant can't be changed through reassignment using the assignment operator, but if a constant is an object, its properties can be added, updated, or removed.

The if...else statement executes a statement if a specified condition is truthy. If the condition is falsy, another statement in the optional else clause will be executed.

The try...catch statement is comprised of a try block and either a catch block, a finally block, or both. The code in the try block is executed first, and if it throws an exception, the code in the catch block will be executed. The code in the finally block will always be executed before control flow exits the entire construct.

The parseInt() function parses a string argument and returns an integer of the specified radix (the base in mathematical numeral systems).

The get syntax binds an object property to a function that will be called when that property is looked up. It can also be used in classes.

Apart from graphic primitives like rectangles and circles, SVG offers a set of elements to embed other types of content in images as well.

The unsigned right shift (>>>) operator returns a number whose binary representation is the first operand shifted by the specified number of bits to the right. Excess bits shifted off to the right are discarded, and zero bits are shifted in from the left. This operation is also called "zero-filling right shift", because the sign bit becomes 0, so the resulting number is always positive. Unsigned right shift does not accept BigInt values.

The diffuseConstant attribute represents the kd value in the Phong lighting model. In SVG, this can be any non-negative number.

A block statement is used to group zero or more statements. The block is delimited by a pair of braces ("curly braces") and contains a list of zero or more statements and declarations.