JavaScript Competency (Intermediate Level)

Topics covered

• assign a function to a variable and pass a function as an argument to another function
• break down and access the components of arrays with array destructuring
• check the type of an object using the instanceOf operator
• create a function from a string using the new keyword
• create a new array by performing an operation on the elements on an existing one using the map() method
• define and invoke a function which returns a nested function
• generate deep and shallow copies of arrays and add and remove array elements
• identify a number of object methods to access the keys and values of an object
• implement an object constructor and use it to instantiate new objects
• initialize an empty object and add/remove properties to/from that object
• insert elements into the middle of arrays using splice and create slices of arrays using the slice method
• perform aggregate and filter operations on the contents of an array using the reduce() and filter() methods
• prevent changes from being made to an object by freezing it
• recognize the role of the "this" keyword within the scope of a JavaScript object
• recognize what data types in JavaScript are passed by value and by reference
• use function callbacks to ensure the sequential execution of functions
• use the call, apply, and bind methods to link a function invocation with an object
• use the call method to link a JavaScript object to a function call
• use the rest parameter syntax to create functions with an undefined number of parameters
• use the spread operator to expand the contents of arrays
• use the spread syntax and the JSON object to create new objects