Why === instead of == for undefined
665
Which equals operator (== vs ===) should be used in JavaScript comparisons?
115437
Javascript || operator
78285
How to check for equals? (0 == i) or (i == 0)
53664
What's the difference between equal?, eql?, ===, and ==?
39485
Why does ('0' ? 'a' : 'b') behave different than ('0' == true ? 'a' : 'b')
92485
JavaScript by reference vs. by value
32886
What is the difference between != and =! in Java?
124671
Why doesn't equality check work with arrays
42605
Is there a technical reason to use > (<) instead of != when incrementing by 1 in a 'for' loop?
68074
JavaScript 'in' operator for `undefined` elements in Arrays
110201
Difference between var = {} and var = []?
158810
Why does >= return false when == returns true for null values?
92055
In JavaScript, why is "0" equal to false, but when tested by 'if' it is not false by itself?
26433
How does variable assignment work in JavaScript?
134742
String comparison in Python: is vs. ==
126174
What is the difference between != and  operators?
99610
The difference between += and =+