1. What happens when this code executes?
var x;
var y=3;
x=y*5;
alert(x);
What happens when this code executes?
We get an error; x isn’t declared
We get an error; alert isn’t defined
15 is shown in a dialog box
15 is printed to the webpage
“x” is shown in a dialog box
“x” is printed to the webpage

2. What happens when this code executes?
var x;
var y=3;
x=y*5;
alert(x);
What happens when this code executes?
We get an error; x isn’t declared
We get an error; alert isn’t defined
15 is shown in a dialog box
15 is printed to the webpage
“x” is shown in a dialog box
“x” is printed to the webpage

3. What happens when this code executes?
var x=5;
var z=x;
x=“stuff”;
document.write(x);
What happens when this code executes?
We get an error; x can’t hold a number and then “stuff”
We get an error; document.write() doesn’t take parameters
“stuff” is printed to the webpage
5 is printed to the webpage

4. What happens when this code executes?
var x=5;
var z=x;
x=“stuff”;
document.write(x);
What happens when this code executes?
We get an error; x can’t hold a number and then “stuff”
We get an error; document.write() doesn’t take parameters
“stuff” is printed to the webpage
5 is printed to the webpage

5. What value will z hold when this finishes?
var x=5;
var y=6;
z=x*y;
z=z*z;
What value will z hold when this finishes?
We get an error; z*z can’t be assigned to z
We get an error; z wasn’t declared
900
27000

6. What value will z hold when this finishes?
var x=5;
var y=6;
z=x*y;
z=z*z;
What value will z hold when this finishes?
We get an error; z*z can’t be assigned to z
We get an error; z wasn’t declared
900
27000

7. What value will x hold when this finishes?
var x=3;
if(x>4) {
x=x+5; }
else
x=x*2;
What value will x hold when this finishes?
We get an error; ‘else’ isn’t declared 8 6 16

8. What value will x hold when this finishes?
var x=3;
if(x>4) {
x=x+5; }
else
x=x*2;
What value will x hold when this finishes?
We get an error; ‘else’ isn’t declared 8 6 16

9. What gets shown in a dialog box when this function is called?
function fun()
var x=3;
var y=4;
alert(x*y);
What gets shown in a dialog box when this function is called?
Nothing; an error occurs because the function is missing ‘{‘ & ‘}’
Nothing; an error occurs because variables cannot be declared in a function
Nothing; an error occurs because this function is missing parameters 12

10. What gets shown in a dialog box when this function is called?
function fun()
var x=3;
var y=4;
alert(x*y);
What gets shown in a dialog box when this function is called?
Nothing; an error occurs because the function is missing ‘{‘ & ‘}’
Nothing; an error occurs because variables cannot be declared in a function
Nothing; an error occurs because this function is missing parameters 12

11. var x=0,z;
for(z=10;z>7;z--) {
x=x+1; }
What is the value of x when this loop finishes (how many times does the code in the loop run)? 3 4 5 6

12. var x=0,z;
for(z=10;z>7;z--) {
x=x+1; }
What is the value of x when this loop finishes (how many times does the code in the loop run)? 3 4 5 6

13. var x=0,z;
for(z=43;z>28;z++) {
x=x+1; }
What is the value of x when this loop finishes (how many times does the code in the loop run)? 14 15 16
Infinite loop

14. var x=0,z;
for(z=43;z>28;z++) {
x=x+1; }
What is the value of x when this loop finishes (how many times does the code in the loop run)? 14 15 16
Infinite loop

15. What is the value of y when this loop finishes?
var x=0, y=1,z,tmp;
for(z=2;z<4;z++) {
tmp=x+y;
x=y;
y=tmp; }
What is the value of y when this loop finishes? 1 2 3 4 5

16. What is the value of y when this loop finishes?
var x=0, y=1,z,tmp;
for(z=2;z<4;z++) {
tmp=x+y;
x=y;
y=tmp; }
What is the value of y when this loop finishes? 1 2 3 4 5

17. Write a javascript function called showValue() that reads the value from this text-field in the html, and shows it in a dialog box:
<input type=“text” id=“txtbox”>

18. Write a javascript function called showValue() that reads the value from this text-field in the html, and shows it in a dialog box:
<input type=“text” id=“txtbox”>
function showValue() {
var x=document.getElementById("txtbox");
alert(x.value); }

19. Given an array named ‘arr’, write javascript code that checks to see if the size of the array is at least 3; if not, it displays “Error” in a dialog box. If so, show, in a dialog box, the sum of the first 3 elements (assume they’re numbers).

20. Given an array named ‘arr’, write javascript code that checks to see if the size of the array is at least 3; if not, it displays “Error” in a dialog box. If so, show, in a dialog box, the sum of the first 3 elements (assume they’re numbers).
If(arr.length<3) {
alert("Error"); }
else
alert(arr[0]+arr[1]+arr[2]);

21. Given an array named ‘arr’, write javascript code that displays, in a dialog box, the sum of all its elements (assume they’re all numbers).

22. Given an array named ‘arr’, write javascript code that displays, in a dialog box, the sum of all its elements (assume they’re all numbers).
var i;
var sum=0;
for(i=0;i<arr.length;i++) {
sum+=arr[i]; }
alert(sum);