COMP 1000: Think Like a Computer: The PreTeXt Interactive Edition

As you begin programming, you’ll see that there are many ways to solve problems. You’ll also find that one of the thrills of programming is how easily you can do things correctly that humans could easily make errors on. For example, you’ll learn how to write just a very small bit of code to find the 1047th character in a sentence that might be thousands of letters long, and you’ll learn how to do the exact same computation on many different pieces of data.

We’ll often tell you in this textbook not to hard-code answers. What does that mean?

Some things in programming you can only do by typing them out. As you’ve seen, when you have to assign a value to a variable, you simply type something like xyz = 6. No other way.

But in most cases, it’s best not to do computation in your head or write complete answers to programming problems out by hand. That’s where hard-coding comes in. “Don’t hard code” basically means, you should rely on your code, your logic, your program, and you should not write things out by hand or do computation in your head – even if you can do so easily.

When you are writing code or working on the answer to a programming exericse, you should ask yourself: Would my answer be correct even if the provided variables had different values? If the answer to that question is no, you’re probably hard-coding, which you should avoid – and there’s probably at least a slightly more concise way to construct your answer!

For example, in this following code, if you’re asked in an exercise to create a variable zx and assign it the value of the sum of the value of y and the value of x, writing zx = 55 is hard-coding.

The operation 20 + 35 may be easy math to do in your head or with a calculator, but when you learn to program, you want to train yourself to notice useful patterns of how to solve problems, which will make your life easier (perhaps beyond programming, even).

The correct way to answer that sort of exercise would be to write: zx = y + x (or zx = x + y, as you were just reminded of the order of operations). That is not hard-coding, and it will be correct no matter what the values of x and y are.

In the code above, if the value of x were 40, 55 would not be the correct value for zx to have. But zx = y + x would still be absolutely correct.

Try as much as you can not to rely on your brilliant but fallible human brain to do computation when you program – use your brain to determine how to write the correct code to solve the problem for you! That’s why we require you to avoid hard -coding for most exercises in this book.