query: in javascript,why null !== undefined is true,but null == undefined also is true?
positive_passages.docid: 665
positive_passages.text: Which equals operator (== vs ===) should be used in JavaScript comparisons?
negative_passages.docid: 53203
negative_passages.text: Checking for undefined
negative_passages.docid: 130399
negative_passages.text: What is the difference between  and !=
negative_passages.docid: 124471
negative_passages.text: Comparing nullable column values using "IS NULL" versus "= NULL"
negative_passages.docid: 38241
negative_passages.text: How do I check for nulls in an '==' operator overload without infinite recursion?
negative_passages.docid: 99447
negative_passages.text: What is the difference between String? and String! (two ways of creating an optional variable)?
negative_passages.docid: 3526
negative_passages.text: How to determine equality for two JavaScript objects?
negative_passages.docid: 151813
negative_passages.text: What does "javascript:void(0)" mean?
negative_passages.docid: 5640
negative_passages.text: How to check a string against null in java?
negative_passages.docid: 109876
negative_passages.text: In the msdn guidance on Equals override, why the cast to object in the null check?
negative_passages.docid: 120997
negative_passages.text: What is the purpose of new Boolean() in Javascript?
negative_passages.docid: 54143
negative_passages.text: Why is the default value of the string type null instead of an empty string?
negative_passages.docid: 126174
negative_passages.text: What is the difference between != and  operators?
negative_passages.docid: 132398
negative_passages.text: What is null in Java?
negative_passages.docid: 33772
negative_passages.text: Is there any difference in equals and == for String variables?
negative_passages.docid: 125415
negative_passages.text: Why is undefined == undefined but NaN != NaN?
negative_passages.docid: 127745
negative_passages.text: Why does 2 == [2] in JavaScript?