Test Your JavaScript Knowledge

Exploring Further: Values vs. References, Function Forms, Coercive Conditional Comparison, and Prototypal "Classes"

• In JavaScript, the decision to assign/pass a value as a reference or as the value itself is entirely determined by the kind of value.
• Primitive values (strings, numbers, booleans, etc.) are always assigned/passed as value copies, while object values (arrays, objects, functions) are held/assigned by reference.
• Anonymous function expressions are named by JS through a process of name inference, but this only happens in limited cases such as when the function expression is assigned with =.
• Named function expressions are explicitly associated with an identifier at compile time, and the identifier takes precedence when assigning a name for the name property.
• There are many function definition forms in JS, including function declarations, function expressions, arrow functions, class methods, and object literal methods.
• Arrow functions are syntactically anonymous and not recommended for frequent use, as they have a specific purpose and should be used appropriately.
• Conditional expressions in JS perform coercion-oriented comparisons, meaning that they perform an implicit value comparison that can involve coercion from one type to another.
• The if statement performs a coercion from whatever type the value is to boolean before making the comparison.
• Prototypal classes are a predecessor to the ES6 class system, and involve linking objects through a prototype chain.
• The Object.create() method can be used to link objects through a prototype chain, and delegation behavior is labeled as "inheritance".
• Functions by default reference an empty object at a property named prototype, which serves as the prototype object to link to when other objects are created by calling the function with new.
• The "prototypal class" pattern is now discouraged in favor of using ES6's class mechanism, which fits the class-oriented design pattern more cleanly.