Which of the following code snippets is more efficient, and why?

<script language=”JavaScript”>

For(i=0; i<document.images.length;i++)

Document.images[i].src=”blank.gif”;

</script>

<script language=”JavaScript”>

Var theimages = document.images;

For(i=0;i<theimages.length;i++)

Theimages[i].src”blank.gif”

</script>

Which are true regarding 'window.onload' and ''?

What does the following JavaScript code do?

Which declaration is not valid?

Which will invoke the browser's Add To Favorite dialog box?

Which one shows the correct result for the code below? var arr = []; arr[0] = 'Jani'; arr[1] = 'Hege'; arr[2] = 'Stale'; arr[3] = 'Kai Jim'; arr[4] = 'Borge'; console.log(arr.join()); arr.splice(2, 0, 'Lene'); console.log(arr.join());

Choose from the following which is true about Javascript

What does Object.keys(x) return given the following x object. var x = { 'a': 1, 'b': 2 };

What is the use of isNaN function

Choose correct answer: 'If you delete an object prototype property, it will..........'

function base(callback){ callback.call({msg:'hi'}) } function message(){ alert(this.msg) }; base(message); which is the value of alert?