1. Registered User
Join Date
Mar 2007
Posts
8

Could someone please shed some light on these questions for me im out of my depth and lost if you could help it would be greatly appreciated....

var lower = 1, upper, total = 0, primeArray = [2,3,5,7,11,13];
upper = window.prompt('please enter a number between 1 and 6', '0');
upper = parseFloat(upper);
while (upper >= lower)
{
total = total + primeArray[lower];
lower = lower + 1;
}
document.write(total);

How many times will the loop body be executed if you enter 4 in response to the
prompt when the program is run?

-------------------------------------------------------------------------
function mysteryFunction (startNum, multiplier)
{
var result = 0;
while (startNum <= 10)
{
result = startNum * multiplier;
document.write(result + ', ');
startNum = startNum + 1;
}
}
The output produced by a call to this function is
6, 8, 10, 12, 14, 16, 18, 20,

Which of the following function calls would produce this output?

A mysteryFunction(2, 6)
B mysteryFunction(6, 2)
C mysteryFunction(3, 2)
D mysteryFunction(2, 3)

2. Registered User+
Join Date
Feb 2006
Posts
2,930
Here's another one:
3. How many members will be in the returned array from mystery3(100) ?
a. 23
b. 24
c. 25

Code:
```function mystery3(n,startN){
startN= startN || 0;
var numberA=[];
var pA=[];
for (var  i= 2; i<= n; i++) numberA[i]= true;
var limN= Math.sqrt(n);
var j=2;
for (var i= j+j; i<n; i= i+j) numberA[i]= false;
for(j= 3; j<= limN; j= j+2){
if(numberA[j]== true) for (i= j+j; i<n; i= i+j) numberA[i]= false;
}
for (i= startN; i< n; i++) if(numberA[i]== true) pA.push(i);
return pA;
}```
And for extra credit:
4. How can you improve the performance of mystery3?
Last edited by mrhoo; 06-05-2007 at 10:13 PM.