As a result of this similarity, null has the 0 type tag, which corresponds to an object. The null value, however, was represented as the NULL pointer, which was 0x00 for most platforms. There were 5 type tags that could be used, and the tag for referencing an object was 0. In the first implementation of JavaScript, values were represented in two parts - a type tag and the actual value. However, this is not the case because of a peculiarity with the way JavaScript was first defined. This would typically mean that the type of null should also be "null". The null value is technically a primitive, the way "object" or "number" are primitives. What's the typeof null? typeof null // "object" To differentiate an Array object from an Object object, we can use the Array.isArray() method. () or () (See JavaScript Array Methods - Mutator Methods). For example, arrays have a property, which will return the number of elements in the array. In JavaScript, arrays are technically objects just with special behaviours and abilities. Those two NaN values are not equal because they are not necessarily the same unrepresentable number. This also explains why not all NaN values are equal.
![types of javascript types of javascript](https://way2tutorial.com/images/js_json_object.png)
It instead means that the value cannot be expressed with numbers. For example- consider the first console.log (), the js starts compiling from left to right. Example: Typeof Number, in this sample, we used ‘’ (strict equality comparison operator) which compare value and type both and then return true or false.
#Types of javascript code
So, the name "Not a Number", doesn't mean that the value is not numeric. Output: Let’s cover all the types one by one dedicating a single code section for each code. However, it is a numeric data type whose value cannot be represented using actual numbers. In this course, you are going to learn some advanced JavaScript. The reason for this is, in computing, NaN is actually technically a numeric data type. JavaScript is one of the most used programming languages for developing web applications. The type of NaN, which stands for Not a Number is, surprisingly, a number. Numbers in JavaScript are stored as 64-bit floats, and can be manipulated using the built-in operators. What's the typeof NaN? typeof NaN // "number" Every programming language has its own way of representing data. This means that, regardless of resultant type, the type of a typeof, will always be a string. If the resultant type of the expression is, for example, a number, what will be returned is "number". What is the type of a typeof expression? Well, the typeof operator always returns a string with the type of the operand passed to it. What's the typeof typeof 123? typeof typeof 123 // "string" However, there are a few cases where it is unclear or misunderstood what the type of the operand should be. In the above examples, it's pretty straightforward what the type of the operands will be. A single variable can only store a single type of data. We refer to these as primitive data types. The five most basic types of data are strings, numbers, booleans, undefined, and null. In addition to "number", the typeof operator can return one of 6 potential results - typeof 123 // "number" In Javascript, there are five basic, or primitive, types of data.
![types of javascript types of javascript](https://cdn.educba.com/academy/wp-content/uploads/2020/03/Primitive-Data-Types-in-JavaScript-Example-1.png)
This will return a string with the type of 123, which, in this case, will be "number". For example, to find the type of 123, we would write - typeof 123
![types of javascript types of javascript](https://datavisioner.net/wp-content/uploads/2020/04/JS-var-type.png)
We will get to them in more advanced tutorials. There are two more advanced types in JavaScript.