3. Data Types


          A data type is a data description. To communicate correctly with values, programming languages need to have distinctive data types. With a number, you can do arithmetic, but not with a word or sentence, because the computer classifies them in an unpredictable way. Six primitive (fundamental) data types exist: strings, numbers, Boolean, null, undefined, and Symbol (new in EcmaScript6). Primitives are able to hold a single value only. Another data type is an object which is not one of these primitives and may contain multiple values. This learning guide will not cover the discussion on object data type.