Generating a Random Number

1. When generating a random number you should assign it to a variable so that it can be used later on in the program. The general statement is

ranNum = Math.floor(Math.random()*highnum)+1

where highnum is replaced with the upper limit of the range of numbers desired.

1. For example if you want random numbers between 1 and 50 you would write

ranNum = Math.floor(Math.random()*50)+1

1. To print out the random number you would use a document.write statement, alert message, etc.

Generating a Certain Number of Random Numbers

1. If you want to generate more than one random number, you can use a for loop. To generate 3 random numbers between 1 and 100 you would type

for (i=1; i<=3; i++) {

someNum = Math.floor(Math.random()*100)+1

document.write(someNum+" ")

}

Counting Within A Loop

1. If you want to keep track of the sum of all of your numbers (i.e. if you want to calculate an average) you use a new variable within your loop. In this example, the variable total is used. Notice that its value has to be set to zero first.

var total = 0;

for (i=1; i<=3; i++) {

someNum = Math.floor(Math.random()*100)+1

document.write(someNum+" ")

total = total + someNum

}

alert(The total of all of your numbers is +total)

1. Once your loop finishes, the variable total will be equal to the sum of all of your random numbers and its value will be given in an alert box.

Assignment #9

1. Write a program where the click of a button will pop up an alert box which tells you the value of a random number between 1 and 100. Once you click on OK, all the numbers from 1 up to that random number are printed out on the page. Save the file as "9a_random.html" in your shared OneDrive folder.

1. Write a program where the click of a button will pop up an alert box which tells you the value of a random number between 1 and 10. Once you click on OK, the sum of all the numbers from 1 up to that random number pops up in an alert box. Your alert messages should tell you what the numbers are. Save the file as "9b_random.html" in your shared OneDrive folder.

1. Write a program where the click of a button will pop up an alert box which tells you the value of a random number between 1 and 10. Once you click on OK, the average of all the numbers from 1 up to that random number pops up in an alert box. Your alert messages should tell you what the numbers are.