Why is NaN === NaN false?
83165
What is the rationale for all comparisons returning false for IEEE754 NaN values?
10287
Why does parseInt yield NaN with Array#map?
153624
What's the difference between is_null($var) and ($var === null)?
110074
What is the difference between == and equals() in Java?
58980
How does the ternary operator work?
119268
Stopping the debugger when a NaN floating point number is produced
106795
What is the use of the := syntax?
41022
Why does the ternary operator unexpectedly cast integers?
12242
How does string equality work in JavaScript?
1469
Is there a difference between "==" and "is"?
43489
Why does Boolean.ToString output "True" and not "true"
134742
String comparison in Python: is vs. ==
126640
In Javascript, why is the "this" operator inconsistent?
79127
How does "if(new Integer(1) == new Integer(1))" work in Java?
139204
Why do numeric string comparisons give unexpected results?
54984
acos(1) returns NaN for some values, not others
63816
In Java, what does NaN mean?