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It's commonly known that {} is shorter way to define an object like [] is for an array.
But now I am wondering why:
{} != ({})
{} evaluates to undefined({}) evaluates to "correct" ObjectWhy is JavaScript behaving like this ?
For example 1 equals to (1), so why {} not equals to ({}) ?
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Each object, each {} is distinct. Same applies to arrays, too. Show activity on this post. 2) it does not make any difference whether you use == or === for comparing objects, because comparing them always returns false.
google doesn't have value (undefined, null) then use {} . It is a way of assigning a default value to a variable in JavaScript. Follow this answer to receive notifications.
The != operator is an equality operator that is used to check whether two operands are equal or not. The =! operator is a combination of two operators, one is an assignment, and the second is a negation operator that works on boolean value.
The !== operator returns true when elements are not equal value or not equal type.
{} != ({})
This is a syntax error.
SyntaxError: Unexpected token !=
{} is ambigious like that. Is it an empty block, or an empty object literal? It's failing because a comparison operator can not follow a block.
Wrapping it with parenthesis makes the parser treat it as an expression. An expression can't contain a block, so it knows it's an object.
However, if you wrap that comparison in an expression...
({} != ({}))
...it's still true because variables which have an object assigned to them's values are a pointer to them and as a consequence, they are never copied around by their contents (though this is irrelevant to your example). Because of this, their pointer is always different and the comparison fails.
This also implies that comparing two variables which point to the same object will work as expected, as their pointers will be the same.
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