You asked: Why is null equal to undefined in JavaScript?

Why does null equal undefined?

The undefined value is a primitive value used when a variable has not been assigned a value. The null value is a primitive value that represents the null, empty, or non-existent reference. When you declare a variable through var and do not give it a value, it will have the value undefined.

Why null == undefined is true in JavaScript?

null and undefined both return false . That’s why your code is actually checking if false is equal to false . However their types are not equal. Because of that, the next statement will return false, as the === comparison operator checks both the types and their value.

Is null equal to undefined in JavaScript?

It means null is equal to undefined but not identical. When we define a variable to undefined then we are trying to convey that the variable does not exist . When we define a variable to null then we are trying to convey that the variable is empty.

Does null == undefined?

null is an assigned value. It means nothing. undefined means a variable has been declared but not defined yet.

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Is it better to return null or undefined?

Undefined typically refers to something which has not yet been assigned a value (yet). Null refers to something which definitively has no value. In that case, I would recommend returning a null. Note that a function with no specified return value implicitly returns undefined.

Is it better to use null or undefined JavaScript?

Only use null if you explicitly want to denote the value of a variable as having “no value”. As @com2gz states: null is used to define something programmatically empty. undefined is meant to say that the reference is not existing.

What is the difference between NULL & undefined?

Many times we often get confused on what the difference between UNDEFINED and NULL is. Simply put, undefined means a variable has been declared but has not yet been assigned a value. … On the other hand, null is an object. It can be assigned to a variable as a representation of no value.

IS NULL check 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.

What is difference between NULL and NULL?

Null has a default value 0. it can be used as bool,integer, pointer. But C# null is used when we are not pointing to some object. I am not sure whether null can be used in place of NULL in C#.

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Is null or undefined Lodash?

Lodash helps in working with arrays, strings, objects, numbers, etc. The _. isNil() method is used to check if the value is null or undefined. If the value is nullish then returns true otherwise it returns false.

Why do I get undefined JavaScript?

Undefined is also a primitive value in JavaScript. A variable or an object has an undefined value when no value is assigned before using it. So you can say that undefined means lack of value or unknown value. … You will get undefined value when you call a non-existent property or method of an object.

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