1, only parameters before the first one with
    // a default value are counted
    

##  Specifications

Specification  
---  
[ ECMAScript Language Specification  
#  sec-function-instances-length
](https://tc39.es/ecma262/multipage/fundamental-objects.html#sec-function-
instances-length)  
  
##  Browser compatibility

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##  See also

  * [ ` Function ` ](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function)

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