PHP: Traversing strings
You can use loops to process strings as well as numbers. Mainly as a way to retrieve a specific character by its index. Below is some sample code that prints the letters of each word on a different line:
<?php
function printNameBySymbol($name)
{
$i = 0;
// This check will be performed until the end of the string
// including the last character. Its index is `line length - 1`.
while ($i < strlen($name)) {
// Getting a character by its index
print_r("$name[$i]\n");
$i = $i + 1;
}
}
$name = 'Arya';
printNameBySymbol($name);
// => 'A'
// => 'r'
// => 'y'
// => 'a'
https://replit.com/@hexlet/php-basics-loops-using-printnamebysymbol
The main thing in this code is to set the right condition in while. This can be done in two ways: $i < strlen($name) or $i <= strlen($name) - 1. Both lead to the same result.
Instructions
Write a function, printReversedWordBySymbol(), which takes a word as input and prints it by character, just as in the example we gave, but does it in reverse order.
<?php
$word = 'Hexlet';
printReversedWordBySymbol($word);
// => 't'
// => 'e'
// => 'l'
// => 'x'
// => 'e'
// => 'H'
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.
languages.lessons.show.chat.guest
Your exercise will be checked with these tests:
1<?php
2
3namespace HexletBasics\Loops\IterationOverString;
4
5use PHPUnit\Framework\TestCase;
6
7class SolutionTest extends TestCase
8{
9 public function test()
10 {
11 require 'index.php';
12
13 $str = 'Hexlet';
14 $expected = "t\ne\nl\nx\ne\nH\n";
15 $this->expectOutputString($expected);
16 printReversedWordBySymbol($str);
17 }
18}
19Teacher's solution will be available in:
