[JoBrad]

JavaScript allows you to access and define object properties in several ways. The key thing to know here is that obj.foo, obj[“foo”], and obj[myProp] are all equivalent, where foo is a property of obj, and myProp is a variable containing the string “foo”.

This behavior is extended into object and class definitions, too. {[myProp]: “value”} creates an object whose property is the value of myProp, while {myProp: “value”} is an object with the property “myProp”. Because of the special nature of Symbols, the bracket notation is used when creating an object or class whose properties include a Symbol.