IS null == true?

IS null == true?

However, if you coerce null to a number it is coerced to +0 so +null == false actually returns true . Answer : There no relative aspect between null and boolean. The value null is a literal (not a property of the global object like undefined can be).

IS null == null in JS?

Summary. null is a special value in JavaScript that represents a missing object. The strict equality operator determines whether a variable is null: variable === null . ... null and undefined are somehow equivalent, still, null represents a missing object, while undefined uninitialized state.

Is null == undefined?

You can see refer to “==” vs “===” article. 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.

Why null === undefined is false?

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 safe?

equals is null safe, however be aware that if two objects are null, object. equals will return true so be sure to check that the objects you are comparing aren't null (or hold null values) before using object.

Is null better than undefined?

so basically null value means a variable has been explicitly set as (no value = null) or has been initialized and defined to be nothing. While undefined means. it was probably never initialized or if it was it was never defined.

Should I use null or undefined?

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. A null value has a defined reference to "nothing".

When to use is null or is not null?

• If the value of expression is NULL, IS NULL returns TRUE; otherwise, it returns FALSE. If the value of expression is NULL, IS NOT NULL returns FALSE; otherwise, it returns TRUE. Remarks. To determine whether an expression is NULL, use IS NULL or IS NOT NULL instead of comparison operators (such as = or !=).

When to return true or false in is not null?

• Specifies that the Boolean result be negated. The predicate reverses its return values, returning TRUE if the value is not NULL, and FALSE if the value is NULL. If the value of expression is NULL, IS NULL returns TRUE; otherwise, it returns FALSE. If the value of expression is NULL, IS NOT NULL returns FALSE; otherwise, it returns TRUE.

What happens if the value of an expression is null?

• Return Code Values. If the value of expression is NULL, IS NULL returns TRUE; otherwise, it returns FALSE. If the value of expression is NULL, IS NOT NULL returns FALSE; otherwise, it returns TRUE.

Is there a way to check for null in JavaScript?

• The good way to check for null is by using the strict equality operator: missingObject === null evaluates to true because missingObject variable contains a null value. If the variable contains a non-null value, like an object, the expression existingObject === null evaluates to false.