Other Types of Operators

• JavaScript has a few additional operators that can be convinient, and are worth mentioning. You likely would not use these as frequently as the other operators already discussed.

1. Type Of : The type of operator returns the data type of a specified variable, object, function, etc.

• Operator: typeof

• Examples:

  let car = "Honda";
  typeof car; //this line returns "string" because the value of car is a string
  let x, y;
  let equation = x + 5 / (6 * y) + 17;
  typeof equation; //this line returns "number" because the value returned from evaluating the equation is a number
  

2. Delete : The delete operator deletes a property from an object

let pet = {name:"Macy", species:"Dog", age:5, attribute:"fluffy"};
delete pet.age;   // removes the age property from the pet object

3. In : The in operator checks to see if a specified property is in a specified object(objects are covered in the next lesson). If the object does contain the property, the operation returns true. Otherwise, it returns false.

pet = {name:"Macy", species:"Dog", age:5, attribute:"fluffy"};
"name" in pet;   // returns true because the pet object has a property called "name"

Exercise 2.6

See the Pen Exercise 2.6 by LSU DDEM (@lsuddem) on CodePen.