PHP: Extracting characters from string

Sometimes, you need to get a single character from a string. For example, if a website knows the user's first name and surname, and at some point, it needs to output it asJ. Smith, you need to take the initial letter from the first name.

<?php

$firstName = 'Alexander';

print_r($firstName[0]); // => A

Square brackets with a number are a special string extraction operator. This number is called an index — the position of the character inside the string. Indexes start with 0 in almost all programming languages, so to get the first character, you must specify index 0. The index of the last element is equal to the length of the string minus one:

<?php

$firstName = 'Alexander';

// The length of the string is 9, so the last index is 8
print_r($firstName[8]);  // => r

// Self-check.  What will this code print?
$magic = '\nyou';
print_r($magic[1]); // => ?

You're allowed to use negative indices. In this case there's a reference to characters starting from the end of the string. -1 is the index of the last character, -2 of the penultimate, and so on. Unlike direct indexing, reverse indexing counts down from -1:

<?php

$firstName = 'Alexander';

print_r($firstName[-1]); // => r

You can use variables as well as numbers as an index. Here's an example that will have the same result of displaying the character A, but the index inside the square brackets is written as a variable instead of a number:

<?php

$firstName = 'Alexander';
$index = 0;

print_r($firstName[$index]); // => A

Instructions

You've been given three variables with the names of different people. Put together and print a word out from the characters in this order:

1. The third character from the first line.
2. The second character from the second line.
3. The fourth character from the third line.
4. The fifth character from the second line.
5. The third character from the second line.

Try using interpolation: you can put individual characters (called via square brackets), as well as variables, inside curly brackets.