I'm trying to use the new (ES6) Map objects in order to represent a map between properties and a value.  I have objects in a form similar to:   {key1:value1_1,key2:value2_1},..... {key1:value1_N,key2:value2_N}   I want to group them based on both...

From: http://www.2ality.com/2011/12/strict-equality-exemptions.html     JavaScript has two operators for determining whether two values are equal:          The strict equality operator === only considers values equal that have the same type.    The �...

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I understand that to compare two strings for equality, the interpreter has to iterate through both strings and compare each character.   That would make the time complexity 0(n) where n is the length of the shortest string.  However, comparing two nu...

I had been going through the ES6 assuming that it would be easy to switch to EcmaScript 2017.  While going through, I got confused about this code  function f (x, y = 7, z = 42) {     return x + y + z } f(1) === 50   Which has ES5 equivalent   functi...

The == operator is really funny. It is usually doesn't behave as one think it will.  This led me to investigate exactly what is happening below the tip of the iceberg, and according to MDN it is as follow:     If the two operands are not of the s...

I want to check this:  if ( typeof myVar != "undefined" && myVar != null )     ...   In other words, I want to check if a variable has a defined value (including 0 or an empty string), but not undefined or null, which I interpret as v...

When I type 2 == {} on Chrome developer tools, it will return false, but when I type {} == 2, I get a Error Uncaught SyntaxError: Unexpected token ==. What's hell == have done?...

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