Is null a primitive type or object type?

user_14284006 0
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https://developer.mozilla.org/en-US/docs/Glossary/Primitive In JavaScript, a primitive (primitive value, primitive data type) is data that is not an object and has no methods. There are 6 primitive data types: string, number, bigint, boolean, undefined, and symbol. There also is null, which is seemingly primitive, but indeed is a special case for every Object: and any structured type is derived from null by the Prototype Chain.

but in Javascript the definitve guide, it says Any Javascript value that is not a number, a string, a boolean, a symbol, a null, or undefined is an object.

So which one is right? Is null an object or not.

javascript
3 Answers

When in doubt, read the official specification, which is essentially the Word of God for JavaScript.

A primitive value is a member of one of the following built-in types: Undefined, Null, Boolean, Number, BigInt, String, and Symbol; an object is a member of the built-in type Object; and a function is a callable object. A function that is associated with an object via a property is called a method.

So, yes, null is a primitive value.

user_95152070

As you can see null, Arrays, and Objects are all Objects. 

console.log(typeof null); console.log(typeof []); console.log(typeof {});

If you wish to test for types like you're thinking, you might want to check this out.

function getType(mixed){
  if(mixed === null){
    return 'null';
  }
  else if(mixed instanceof Array){
    return 'array';
  }
  return typeof mixed;
}
class Test{
  constructor(){
  }
  method(){
    return this;
  }
}
function ConstructorTest(){
  let privateVarsOk;
  this.method = ()=>{
    return this;
  }
}
const test = new Test; constructorTest = new ConstructorTest;
console.log(getType(null));
console.log(getType('4'));
console.log(getType(4));
console.log(getType(['a', 2, 'c']));
console.log(getType({}));
console.log(getType(getType));
console.log(getType(function(){}));
console.log(getType(()=>{}));
console.log(getType(Test));
console.log(getType(test));
console.log(getType(ConstructorTest));
console.log(getType(constructorTest));
console.log(getType());

Notice that classes are actually functions though, as they do no introduce a new hierarchy.

user_24384230 
var nullVar=null;
console.log("Data type of nullVar is :"+ (typeof nullVar));

o/p;-Data type of nullVar is :object

Null is primitive datatype but it returns object ... So, null return bogus return value ..

user_160906550
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