• Adobe After Effects Expressions

  Looping through numProperties always ends with error: undefined

  Posted by Hugo Van den doel on June 24, 2019 at 4:08 pm

  Working on a function that checks wether the selected layer has a specific effect applied to it. Here’s a simplified version of it:

  function hasTransformEffect(layer) {
for (i = 1; i <= layer.Effects.numProperties; i++) {
alert(i);
}
}

  alert(hasTransformEffect(app.project.activeItem.selectedLayers[0]));

  When running this, I always end up with an undefined after it’s finished looping. Here’s a video of me trying this https://streamable.com/bcg48

  Few things I have tried:
  – Using a try/catch to bypass it
  – Using an if statement to check wether numProperties > 0 before running the loop
  – Running it from Extendscript IDE
  – Running it from a saved .jsx file
  – Running it on a different machine
  – Running it on a different version of AE

  Wondering what I’m missing, I’m assuming it’s something about numProperties that I don’t know. Any help is greatly appreciated!

  Hugo

  Andrei Popa replied 6 years, 10 months ago 2 Members · 1 Reply
• 1 Reply

• 

  Andrei Popa

  June 25, 2019 at 6:19 am

  Why do you use the last alert? That is what give undefined. You have an alert inside the function that works ok. Then, when you try to allert the result of the function, it is undefined. To change that either remove the last alert, or return something with the function.

  Andrei
  My Envato portfolio.

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