Tasks

First impressions are rarely the best, but they are certainly what we remember for the rest of our lives. We're talking about programming, in case you were wondering. In this task, we will try to calculate the square of a number, display it on the screen, and also use the ability to read data from the keyboard (the user will enter the number while the program is running).

Here's a riddle: "Written once, it runs everywhere". Answer: A Java program. That's the right answer, because Java is logical and properly structured. Let's rephrase this slogan for students: "learn once, use anywhere!" Here's a little task on this topic: write a program that displays a useful phrase 10 times on the screen.

What if you don't abandon your studies? What if you keep on completing tasks and working through the lessons? If you do, then by next New Year's, which is at least three months away, you can celebrate the new year as a real programmer! That's the dream. But for now, let's go to work. Let's remove the unnecessary comments and display some New Year's well-wishes.

Editing someone else's code is sometimes more difficult than writing your own. You can trust the experience of experts at the secret CodeGym center. That's why our curriculum includes tasks about fixing code. For now, let's open our textbook, wrap our brains around some simple code, and then change the code so that the variable name takes the value "Amigo".

Articles such as "1001 Tips for Becoming a Great Programmer" almost always include a phrase like "Someone else's code will teach you how to write your own". A programmer seldom works alone, so this advice is the plain truth. You won't get anywhere by ignoring it. We have to get used to teamwork and fixing other people's code.

Comments are much more useful than they may seem at first glance! You can use them to hide your innermost thoughts from the compiler! Only your fellow programmers will be able to read them. Anyway, our program has some extra lines that prevent it from working as it should. Fix the problem by commenting out the superfluous lines.

You've got someone else's code in front of you. It's mysterious and incorrect. But programming power is concentrated in your hands. You can change everything, and the compiler will even help you with this task. What do you need to do to restore the delicate balance and peace? Just change the program so that the variable age takes the value 15.

Many programmers are just crazy about brainteasers: Rubik's cubes, "use two matchsticks to get 100", the Tower of Hanoi, and others. Their brains are wired like that. Let's practice solving some brainteasers in programs. In this case, arrange the plus and minus signs so that the variable result is equal to 20.

Your mentors at the secret CodeGym center are really into being original! Everyone usually starts learning how to program with the phrase "Hello World!", but that's so ordinary! Diego came up with a cheer just for you. Here it is. Display it on the screen.

The rule "Always read the terms of the contract!" seems simple enough, but so many people get burned because they don't follow it! But programmers are not like that. They always carefully study project conditions/specifications and only then do they draw conclusions, make plans, and start working. Let's practice a useful skill: we'll change the terms of the contract to be more favorable.

If you show me someone who has never once made a programming error, we can say with certainty: you must not be talking about a human. Bug-free programming just doesn't happen. But this isn't so scary. The most important thing is to immediately accept that bugs are inevitable. We search for (or "catch", as professionals sometimes say) and correct bugs.

Inexperienced and, at times, experienced programmers create superfluous code. Just in case. For example, they may declare a couple dozen variables and then not know what to do with them. In this task, someone did something weird, and we get to correct it. Look for unused variables and convert them to comments in order to hide from the compiler.