How do I remove a property from a JavaScript object?

tl;dr

To remove a property from an object (mutating the object), you can use the delete statement. For example:

let myObject = {
  "ircEvent": "PRIVMSG",
  "method": "newURI",
  "regex": "^http://.*"
};

delete myObject.regex;

Alternatively, you can use object destructuring to create a new object with all the keys of the original except some. For example:

let myObject = {
  "ircEvent": "PRIVMSG",
  "method": "newURI",
  "regex": "^http://.*"
};

// assign the key regex to the variable _ indicating it will be unused
const {regex: _, ...newObj} = myObject;

console.log(newObj);   // has no 'regex' key
console.log(myObject); // remains unchanged