Javascript ReferenceError: Invalid Left-hand Side in Assignment

So lately was trying some silly syntax with javascript, logically it seems to work, but throw away your dry logic!

Most of us who have been pawing at some raw JS knows undefined || “hi” would result in “hi”, on the same lines, /me tried :

obj={} Object

obj[“prop”] || obj[“prop”] = “newprop”

ReferenceError: Invalid left-hand side in assignment

arguments: Array[0]
get message: function () { [native code] }
get stack: function () { [native code] }
set message: function () { [native code] }
set stack: function () { [native code] }
type: "invalid_lhs_in_assignment"
__proto__: Error

obj[“prop”] = obj[“prop”] || “newprop”

obj.prop “newprop”

Works this way ^_ ^

One of my friend @Altreus said “Lack of ||= saddens me” and @jasonmulligan solution helped!

Finally:

• ||= is much needed.
• obj[‘prop’] ||= “fun”
• There is already a proposal in ES5 for this now!

Happy hacking, hope we shall have more fun with more JS :)

EDIT 0 suggested by charliesome:

obj[“prop”] || (obj[“prop”] = “newprop”);