What is null data type in JavaScript?

Why do we use null in JavaScript?

In JavaScript, the value null represents the intentional absence of any object value. null expresses a lack of identification, indicating that a variable points to no object. The global undefined property represents the primitive value undefined .

What is datatype null?

Datatype for NULL is as meaningless as datatype for 0 : it can be INTEGER , FLOAT or a VARCHAR . You cannot tell it just from the value. NULL is legitimate value in almost every datatype domain, which means the absence of actual value.

What are JavaScript data types?

JavaScript types

  • Primitive values (immutable datum represented directly at the lowest level of the language) Boolean type. Null type. Undefined type. Number type. BigInt type. String type. Symbol type.
  • Objects (collections of properties)

What are 3 types of data in JavaScript?

JavaScript allows you to work with three primitive data types: numbers, strings of text (known as “strings”), and boolean truth values (known as “booleans”). JavaScript also defines two trivial data types, null and undefined, each of which defines only a single value.

Is NULL better than undefined?

null is a special value meaning “no value”. null is a special object because typeof null returns ‘object’. On the other hand, undefined means that the variable has not been declared, or has not been given a value.

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Is object NULL JavaScript?

In order to be able to query this difference, JavaScript has null and undefined : While null is – just like in other languages an object, undefined cannot be an object because there is no instance (even not a null instance) available. null is an object.

Can Smallint be null?

The string must contain a valid string representation of a number. The result is the same number that would result from CAST(string-expression AS SMALLINT) . … The result of the function is a small integer. The result can be null; if the argument is null, the result is the null value.

What is null in Java?

In Java, null is a reserved word for literal values. It seems like a keyword, but actually, it is a literal similar to true and false.

What is JSON format?

JavaScript Object Notation (JSON) is a standard text-based format for representing structured data based on JavaScript object syntax. It is commonly used for transmitting data in web applications (e.g., sending some data from the server to the client, so it can be displayed on a web page, or vice versa).

Is array a data type?

In computer science, an array type is a data type that represents a collection of elements (values or variables), each selected by one or more indices (identifying keys) that can be computed at run time during program execution. Such a collection is usually called an array variable, array value, or simply array.

What is === in JavaScript?

=== (Triple equals) is a strict equality comparison operator in JavaScript, which returns false for the values which are not of a similar type. This operator performs type casting for equality. If we compare 2 with “2” using ===, then it will return a false value.

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