CODEWITHSUNDEEP
javascriptphp
John
John

Reputation: 13729

JavaScript JSON associative object key and value both as datetime stamp

My variable date_mplayer simply stores a PHP generated time() stamp. I need to create an array with a key/value pair which both the key and value are initially the same time stamp from date_mplayer.

What I've got at the moment:

var md = {date_mplayer:date_mplayer};
localStorage.setItem('date_mplayer', JSON.stringify(md));

If I console.log(localStorage); I get...

date_mplayer "{"date_mplayer":1427837963}"

What I need should look something like:

date_mplayer "{1427837963:1427837963}"

Background: this is how I will pass function commands to a music player across tabs based on each tab's assigned date. Every X number of seconds the JSON object will be reconstructed with the updated timestamp for the tab's key representation; tabs not updated within a span of time a few seconds longer will have their keys removed (to prevent eternal growth until it hits the browser storage limit).

No frameworks.

Upvotes: 1

Views: 224

Answers (2)

Mitya
Mitya

Reputation: 34556

Object keys, when written in object literal syntax, are non-dynamic; that is to say, you can't use variables in their place. The key will be named literally what you type there, so:

var foo = 'bar', obj = {foo: foo};
obj.foo; //bar
obj.bar; //undefined

Instead, to set a dynamic key name, you need to set the key via square-bracket syntax after the object has been created, passing the key name as a string:

var foo = 'bar', obj = {};
obj[foo] = foo;
obj.bar; //bar

Upvotes: 1

Plato
Plato

Reputation: 11052

var md = {};
md[date_mplayer] = date_mplayer;
localStorage.setItem('date_mplayer', JSON.stringify(md));

Upvotes: 1

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