Default Parameters on Functions

Aitor Gandia

Snap Lens Network Member Lens Studio Team

May 15, 2019 08:24

I can't find any reference to this feature on the guides or scripting API and I wonder why it is not implemented.

it would be really helpful to be able to do something like

myfunction() and myfunction( value1 )

function myfunction( parameter1 = "defaultvalue" ){

dosomethingwithparameter1(parameter1);

}

where the option to not give a parameter is backed up by the default value.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Default_parameters

Keep up the good work!

best regards.

0

Jacob
Snap Lens Network Member Lens Studio Team

May 28, 2019 17:36
Hi Aitor,

Lens Studio supports an older version of javascript from before that feature was added, so unfortunately it's not currently available. We may support it in the future though!

In the meantime, you can follow a workaround on the page you linked to:
```
function myFunction(a) {
  a = (typeof a !== 'undefined') ?  a : "defaultValue";
  return a;
}

myFunction("test"); // returns "test"
myFunction(); // returns "defaultValue"
```
Basically, if a parameter isn't given it defaults to undefined. So you can check if a parameter is undefined and use your default value instead. This is less convenient than the built-in version but hopefully should still help!

Let me know if you have any more questions!

Jacob
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Aitor Gandia
Snap Lens Network Member Lens Studio Team

May 29, 2019 07:12
Oh, I see.

I have been using the workaround so far but it'd be nice to have the feature in the future.

Thank you for your response!

Best regards.
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