Javascript arrays undefined values

Question

I have some code that produces undefined values in an array making no sense.

here is the code:

gcc_py = 8;
gcc_pyd = 12;
var aci = 360/gcc_pyd;
var parcalar = new Array();
var renkler = new Array();

for(var i = 0;i<gcc_pyd;i++){   
    parcalar.push(aci);
    renkler.push('#000');
}

console.log(parcalar);
console.log(renkler);

console.log(parcalar) outputs this:

[ Object , Object , Object , Object , Object , Object , Object , Object , Object , Object , undefined × 2]

do you have any idea for the undefined values in the array?

It outputs [30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30] for me. — sachleen
– sachleen, Commented Jun 21, 2012 at 18:10
Also, please change new Array(); to [] it's considered better practice — Benjamin Gruenbaum
– Benjamin Gruenbaum, Commented Jun 21, 2012 at 18:11
@exculuber: What are the contents of the Objects you're seeing in the console? — gen_Eric
– gen_Eric, Commented Jun 21, 2012 at 18:21

Community · Accepted Answer · 2017-05-23 11:56:20Z

2

I guess you are changing the arrays afterwards. The console will reflect these changes, e.g. then showing objects instead of numbers and strings. Also, when deleting properties from an array (via delete, see Deleting array elements in JavaScript - delete vs splice), they will still show up as initialised but empty (see What is "undefined x 1" in JavaScript?).

edited May 23, 2017 at 11:56

CommunityBot

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answered Jun 21, 2012 at 18:23

Bergi

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2 Comments

Yunus Eren Güzel Over a year ago

yes, after these lines there is a function call in which these arrays are passed. The function changes the array. Thank you for the answer. Do you have further information about this concept may be a documentation, link, etc?

Bergi Over a year ago

documentation about what? For console you'll find getfirebug.com/logging or patik.com/blog/complete-cross-browser-console-log helpful.

sachleen · Accepted Answer · 2012-06-21 18:14:49Z

0

The output for me shows

[30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30]

["#000", "#000", "#000", "#000", "#000", "#000", "#000", "#000", "#000", "#000", "#000", "#000"]

Maybe you've added some .prototype stuff to Array somewhere else in the code?

edited Jun 21, 2012 at 18:14

sachleen

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answered Jun 21, 2012 at 18:13

demiurg

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1 Comment

Yunus Eren Güzel Over a year ago

I'm using raphael.js and its plugin piechart.js

JCSickmeyer · Accepted Answer · 2012-06-21 18:15:33Z

0

When I run the same configuration:

<script>
  var gcc_py = 8;
  var gcc_pyd = 12;
  var aci = 360 / gcc_pyd;
  var parcalar = new Array();
  var renkler = new Array();

  for(var i = 0; i < gcc_pyd; i++){
      parcalar.push(aci);
      renkler.push('#000');
  }

  console.log(parcalar);
  console.log(renkler);
</script>

I get:

[30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30]
["#000", "#000", "#000", "#000", "#000", "#000", "#000", "#000", "#000", "#000", "#000", "#000"]

not sure what you're seeing.

answered Jun 21, 2012 at 18:15

JCSickmeyer

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1 Comment

Yunus Eren Güzel Over a year ago

My console outputs it as an array of objects do you have any idea for that?

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