To check null in JavaScript, use triple equals operator(===) or Object is() method. If you want to use Object.is() method then you two arguments. 1) Pass your variable value with a null value. 2) The null value itself. To find the difference between null and undefined, use the triple equality operator or Object is() method. To loosely check if the variable is null, use a double equality operator(==). The double equality operator can not tell the difference between null and undefined, so it counts as same. So if you want to strict check, then don't use a double equality operator. It will lead to misconclusion.
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