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Why does typeof null return object?
The reasoning behind this is that null , in contrast with undefined , was (and still is) often used where objects appear. In other words, null is often used to signify an empty reference to an object. When Brendan Eich created JavaScript, he followed the same paradigm, and it made sense (arguably) to return “object”.
What is the output of typeof null?
In JavaScript null is “nothing”. It is supposed to be something that doesn’t exist. Unfortunately, in JavaScript, the data type of null is an object. You can consider it a bug in JavaScript that typeof null is an object.
Can an object have a null value?
null is a special value meaning “no value. undefined is not an object, its type is undefined.
What is the value of typeof undefined == typeof null?
The typeof undefined is the string “undefined” — and undefined is a falsy value that is loosely equal to null but not to other falsy values.
How do you check for null in JavaScript?
Javascript null is a primitive type that has one value null. JavaScript uses the null value to represent a missing object. Use the strict equality operator ( === ) to check if a value is null . The typeof null returns ‘object’ , which is historical bug in JavaScript that may never be fixed.
How do you know if an element is null?
To check if it is null, we call the isNull() method and pass the object getUserObject as a parameter. It returns true as the passed object is null.
Why is null an object in JS?
The JavaScript specification says about null : null is a primitive value that represents the intentional absence of any object value. If you see null (either assigned to a variable or returned by a function), then at that place should have been an object, but for some reason, an object wasn’t created.
How do I check if typeof is null?
The typeof keyword returns “object” for null , so that means a little bit more effort is required. Comparisons can be made: null === null to check strictly for null or null == undefined to check loosely for either null or undefined.
How do you check if something is null in JavaScript?
JavaScript uses the null value to represent a missing object. Use the strict equality operator ( === ) to check if a value is null . The typeof null returns ‘object’ , which is historical bug in JavaScript that may never be fixed.
Why is null a type of return value in JavaScript?
In the first implementation of JavaScript, JavaScript values were represented as a type tag and a value. The type tag for objects was 0. null was represented as the NULL pointer (0x00 in most platforms). Consequently, null had 0 as type tag, hence the “object” typeof return value. ( reference)
Is it possible to return a null value in C++?
You can implement a special object of your design that you logically treat as “null” but it’s not part of the C++ language. The NULL return value would only be valid if you were returning a pointer to a Normal object, NULL represents a null pointer, not a null object. What I would do in this case is define a ‘null’ or invalid state for this object.
Is it possible to return a null object from an API?
In essence relying on null properties is not such a good approach it’s better to make those properties undefined or just to return a flat Object from your API. Hope this helped. Approach using .some () instead of .every ():
Why do JavaScript objects return NULL instead of undefined?
The reasoning behind this is that null, in contrast with undefined, was (and still is) often used where objects appear. In other words, null is often used to signify an empty reference to an object. When Brendan Eich created JavaScript, he followed the same paradigm, and it made sense (arguably) to return “object”.