What’s the point of using integers when you could simply code programs using floating-point values all the time to always get the best results? The reason is a good one, but it takes some explaining.
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Unique Random Numbers
The goal is to write code that generates random numbers, but never the same value twice. After all, if you’re coding a card game or generating lotto picks, it’s unrealistic to expect the same value appear multiple times.
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Pick a Card, Any Card
Last week’s Lesson discussed how to monitor random numbers by using an array: When a random value is drawn, it’s corresponding array element is incremented. By continuing that same thought, you can easily ensure that the same random number isn’t used when programming a card game. But first, the game itself!
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Never the Same Number Twice
One of the most common questions I get from my For Dummies programming titles is regarding the lotto programs. That code demonstrates how you can randomly draw lotto balls without drawing the same ball twice.
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The Caesarian Cipher
A Caesarian Cipher is one of the simplest, weakest forms of encryption. Supposedly developed by Julius Caesar, it’s a letter substitution cipher: A becomes C, B becomes D, C becomes E, and so on.
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The Difference Between NULL and Zero
University professors will try to drive the point into your head all semester: NULL and zero are not the same thing! But yet, you’ve looked into memory, you’ve examined the code. That thing they call NULL sure does look like a zero! What’s the big difference?
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What is True?
True is a logical condition. It’s often written TRUE just to confuse it with “true” which is a word that has other implications. But for programming, TRUE generally means success. It’s the opposite of FALSE, which generally means failure.
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For Ever
The most basic and perhaps ancient of programming techniques is the loop. And the most basic loop is the for loop. It’s also pretty flexible.
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Multiplying Without Multiplication
Long, long ago, I was an ardent assembly language programmer. I admired coding in assembly because the programs were small and fast. On the early microcomputers, that was a plus.
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We Have a Winnah!
The game of Tic-Tac-Toe is played on a simple 3-by-3 grid, what C programmers would call a matrix. It’s not The Matrix, of course, but it’s a simple array in which players can battle.
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