JavaScript: Math functions in JavaScript
Explaining functions in JavaScript is somewhat complicated by the language structure. It first appeared in browsers and had very limited capabilities compared to general-purpose languages. It has changed over time as JavaScript has become a powerful language that has taken over client-side development and is heavily used on servers. However, the legacy has stayed, as backward compatibility needs to be maintained. So some parts of language are inconsistent, which can't be explained by the system. You can only dismiss them and say, "That's just how it's always been."
Among these "things" are math functions. In the previous task, we defined the function pow() ourselves (we added it to our practice section), but now let's look at its built-in version in the language itself.
Math.pow(2, 3); // 8
What is Math? Technically, it's an object accessible from any part of the program, but objects are far ahead for now. So far, just remember that we call functions for mathematical operations via Math. This prefix doesn't affect the concept of a function which we discussed earlier and will discuss again later.
A complete list of Math functions is available in the documentation. We'll discuss how to read it later on.
Instructions
Print the absolute value of the number in the soldiersCount variable using the Math.abs() function. The function returns the absolute value of the given number. The absolute value of a number is the number without regard to any sign before it.
Math.abs(-3); // 3
Math.abs(3); // 3
Math.abs(0); // 0
The exercise doesn't pass checking. What to do? 😶
If you've reached a deadlock it's time to ask your question in the «Discussions». How ask a question correctly:
- Be sure to attach the test output, without it it's almost impossible to figure out what went wrong, even if you show your code. It's complicated for developers to execute code in their heads, but having a mistake before their eyes most probably will be helpful.
In my environment the code works, but not here 🤨
Tests are designed so that they test the solution in different ways and against different data. Often the solution works with one kind of input data but doesn't work with others. Check the «Tests» tab to figure this out, you can find hints at the error output.
My code is different from the teacher's one 🤔
It's fine. 🙆 One task in programming can be solved in many different ways. If your code passed all tests, it complies with the task conditions.
In some rare cases, the solution may be adjusted to the tests, but this can be seen immediately.
I've read the lessons but nothing is clear 🙄
It's hard to make educational materials that will suit everyone. We do our best but there is always something to improve. If you see a material that is not clear to you, describe the problem in “Discussions”. It will be great if you'll write unclear points in the question form. Usually, we need a few days for corrections.
By the way, you can participate in courses improvement. There is a link below to the lessons course code which you can edit right in your browser.
Your exercise will be checked with these tests:
1import { expectOutput } from 'hexlet-basics/tests';
2
3const expected = '2309';
4expectOutput(expected);
5Teacher's solution will be available in:
