Null is an object type that represent the null, nothing, empty or non-existent value. You can declare a variable with null value. Null is a special keyword.
let variable_null =null; console.log(variable_null); // output : null
Undefined means a variable has been declared without assign any value.
let variable_undefined; console.log(variable_undefined); // output : undefined console.log(typeof undefined); // output : undefined
You can also set the undefined value explicitly.
let variable_undefined = undefined; console.log(variable_undefined); // output : undefined
Null | Undefined |
Value is assigned |
Value is not assigned |
typeof object |
typeof undefined |
console.log(undefined ==null);
|
console.log(undefined ===null) //false;
|