Which of the following is the best reason for not using "for...in" with array iteration?

Which is not a valid JavaScript operator?

Which is an invalid function declaration?

Which is used to solve the problem of enumerations in JavaScript?

Which will determine if the user's browser is named 'Netscape'?

Which code snippet will trigger an input type='file' attribute when an element with a 'newbtn' ID is clicked? Upload

var a = [2, 5, 12, 16, 23, 35]; XXXX function abc( YYYY ) { return val > 20; } Which option will replace XXXX and YYYY in order to generate 4 as an output?

Using DATE object which call a function based on elapsed time?

In relation to sealing an object globally, which methods returns true if adding, removing, and changing properties is forbidden and all the current properties are configurable: false, writable: false?

In relation to object oriented JavaScript, which option can be used as the value of F.prototype?

Which function of the Object constructor with regard to JavaScript 1.8 returns the array of names of only enumerable properties of the given object?