changing Elements in javascript

Question

fil out the blanks,
I have managed to work out 2 out of 3, and now stuck as I have tried every thing I have learn'ed so far and still coming unstuck.

var arr = document.

getElementsByTagName ("img);

for(var x=0; x<arr. ; x++) {

arr[x]. src = "demo.jpg";

}
I thought it would have been (arr. doucment) and document was the missing word but it's not.
Please any help would be great thank you

Answer 1

length

Try to learn the course again

Answer 2

thank you for the reply,