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PHP: Data Aggregation (Strings)

You can use aggregation with strings as well as with numbers. In most cases, this applies to dynamic string generation, where you don't know in advance what size the string will be and what it will contain.

Imagine a function that multiplies a string, i.e., it repeats a string a given number of times:

<?php

repeat('hexlet', 3); // 'hexlethexlethexlet'

The core mechanism of this function is simple, the loop increments through the string a given number of times:

<?php

function repeat($text, $times)
{
    // For strings, the neutral element is an empty string
    $result = '';
    $i = 1;

    while ($i <= $times) {
        // Add a string on each iteration
        $result = "{$result}{$text}";
        $i = $i + 1;
    }

    return $result;
}

Let's break down down the code's execution into steps:

<?php

// To call repeat('hexlet', 3);
$result = '';
$result = "{$result}hexlet"; // hexlet
$result = "{$result}hexlet"; // hexlethexlet
$result = "{$result}hexlet"; // hexlethexlethexlet

Instructions

Write a function, joinNumbersFromRange(), which joins all numbers in a range into a string:

<?php

joinNumbersFromRange(1, 1); // '1'
joinNumbersFromRange(2, 3); // '23'
joinNumbersFromRange(5, 10); // '5678910'
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:

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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.

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I've read the lessons but nothing is clear 🙄

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