Assignment Order in Javascript [duplicate]

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Something I don't get in the following snippet: a and b are now pointers to the same object.

var foo = {n:1}; /// foo points to an object
var bar = foo;  /// bar point to the same object as foo
foo.x = foo = {n:2};  /// foo is now pointing to a new object

In the last assignment, property x is added to bar. Why? Shouldn't x point to n:2?

Dmitriy · Accepted Answer · 2016-02-29 12:59:44Z

0

foo.x = foo = {n:2};  /// foo is now pointing to a new object

you can simplify as

foo = {n:2}; // foo point to a NEW object
foo.x = foo;

so x is point to foo. property link to itself object.

answered Feb 29, 2016 at 12:59

Dmitriy

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2 Comments

badigard Over a year ago

If I run this as script in Chrome, it appears that bar has new property. foo: Object n: 2 bar: Object n: 1 x: Object foo.x: undefined

Bergi Over a year ago

This answer is wrong.

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