• Adobe After Effects Expressions

  Storing a list of properties in a variable

  Posted by Campion Kirkham on December 4, 2020 at 5:14 am

  I have a list of properties that I want to iterate through to see if they are keyed:

  var testLayer = compItem.layer(1);
  var testProps = ["Position", "Opacity"];
  //This line returns the correct number of position keys on the first layer
  $.writeln(testLayer.Position.numKeys);
  //This line returns the correct number of opacity keys on the first layer
  $.writeln(testLayer.Opacity.numKeys);
  //Both of these lines error out as "undefined is not an object"
  $.writeln(testLayer.testProps[0].numKeys);
  $.writeln(testLayer.testProps[1].numKeys);

  Why is it that I am able to access each property’s keys by directly putting in the string name, but putting that same string in a variable returns undefined?
  Thanks!

  Campion Kirkham replied 5 years, 9 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Dan Ebberts

  December 4, 2020 at 3:36 pm

  Try it this way:

  	$.writeln(testLayer.property(testProps[0]).numKeys);
  	$.writeln(testLayer.property(testProps[1]).numKeys);
• 

  Campion Kirkham

  December 9, 2020 at 5:41 pm

  That worked like a charm, thanks so much!

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