Js data type

• JavaScript has five basic data types and three reference data types (complex data types).
  • The simple data types are String, Number, Boolean, NULL, and Undefined.
  • The referenced data types are Object, Function, and Array

Methods for detecting data types

• There are two common methods for detecting the data typeof a data, namely typeof and instanceof
  • Typeof: Used to detect 5 simple data types, not complex data types.
  • Instanceof: Used to detect complex data types.
  • Test example:

  console.log(typeof('abc')); //String
  console.log(typeof(123));   //Number
  console.log(typeof(true));  //Boolean
  console.log(typeof());      //NULL
  console.log(typeof(abc));   //Undefined
  
  console.log([] instanceof Array);                   // true
  console.log({} instanceof Object);                  // true
  console.log(function(){} instanceof Function);      // true
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