There are very few places where you ever need to use let or var. const is solving important issues - it has lexical scope instead var function scope - it d

There are very few places where you ever need to use let or var. const is solving important issues - it has lexical scope instead var function scope - it does not hoist like var - it prevents accidental reassignment Accidental reassignment happen more often in JS because of non-lexial scoping, weakly typed and async functions. Also, both Ruby and Python are "strongly typed" as opposed to weakly typed Javascript.