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random background color choosing in jsp

Ricky James
Ranch Hand

Joined: Mar 26, 2007
Posts: 83
Hello,

I have a code in which I use Math.random() to select from a set of 3 colors. When I go on refreshing the browser (Firefox) it keeps displaying the background in one of the three colors. But a couple of times I also had "white" as the background color.

MY QUESTION: Why do I get white background even though it is not one of the colors I have in my set?

Thanks

Ricky

Paul Clapham
Bartender

Joined: Oct 14, 2005
Posts: 18992
    
    8

In that code you create five different random numbers. If the first is less than 0.3, you use green. If the second is greater than 0.3 and the third is less than 0.5, you use blue. If the fourth is greater than 0.5 and the fifth is less than 0.8, you use red.

There's plenty of scope for not using any of those three colours here; for example if the first was 0.72 and the second was 0.117 and the fourth was 0.44.

But obviously you meant to use only one random number. If you fixed your code to get a random number and assign it to a local variable, then to always compare against that variable, you would then only have to worry about what would happen if it was over 0.8.
Ricky James
Ranch Hand

Joined: Mar 26, 2007
Posts: 83
Originally posted by Paul Clapham:
In that code you create five different random numbers. If the first is less than 0.3, you use green. If the second is greater than 0.3 and the third is less than 0.5, you use blue. If the fourth is greater than 0.5 and the fifth is less than 0.8, you use red.

There's plenty of scope for not using any of those three colours here; for example if the first was 0.72 and the second was 0.117 and the fourth was 0.44.

But obviously you meant to use only one random number. If you fixed your code to get a random number and assign it to a local variable, then to always compare against that variable, you would then only have to worry about what would happen if it was over 0.8.


O I got it.

Thank you so much Paul. Much appreciated.

Ricky
Srikkanth Mohanasundaram
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Joined: Feb 07, 2007
Posts: 185
That was cool Paul
 
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