Array concatenation variations: Combining two arrays using different techniques.
Array copying variations: creating a new array with the same elements as an existing array.
Comparison statements: conditionally branching in a function based on simple comparisons.
Variable comparison operators.
Variable guards: checking whether a variable is defined or of a certain type.
Loop variations: Converting an array of integers into an array of booleans satisfying a conjunction of two simple relational operations.
Object literal vs. Map: retrieving values.
Object literal vs. Map: creating a map.
Object iteration: different ways of iterating over properties of an object and concatenating property names into a single string.
Recursion variations: Calculating sum of array of integers. Profile contains a simple for-loop for reference.