Writing PHP code without special characters

Question

There is a way to print special characters in PHP using ascii code only?

For example, in javascript, we can use u00e1 in the middle of the text. In Java, we can use u2202 for example.

What about PHP? How do I use it?

I don’t want to include special characters in my code.

Answer 1

What’s new in PHP7:

• Unicode code escape syntax

There is support for Unicode code escape syntax, for example:

<?php
echo "\u{00e1}\n";
echo "\u{2202}\n";
echo "\u{aa}\n";
echo "\u{0000aa}\n"; //o mesmo que o anterior mas com zeros a esquerda
echo "\u{9999}\n";

Will be printed as:

á
∂
ª
ª
香

Example in the ideone: https://ideone.com/2Tcsed

Note 1: The \n is only for line breaking is just to separate the echos, in HTML use <br>

Note 2: Only double quotes support this, single quotes like this echo '\u{aa}'; won’t work

---

Escape syntax in PHP5

In PHP before 7 (ie 5) there was (and still exists) this syntax:

\x[0-9A-Fa-f]{1,2}

That uses hexadecimal notation and is limited to 1 or 2 digits after the \x and just like Unicode (\u{[0-9A-Fa-f]+}) should also be used in double quote notations.

Then to write a Unicode character it will be necessary to use two or more times the \x (since single characters are formed like this), for example \xc3\xa1 would amount to \u{00e1}, example both print á:

<?php
echo "\xc3\xa1\n";
echo "\u{00e1}\n";

Comparing both:

if ("\xc3\xa1" === "\u{00e1}") {
    echo 'São iguais';
} else {
    echo 'São diferentes';
}

Will display São iguais

• Link: http://php.net/manual/en/language.types.string.php#language.types.string.syntax.double

---

Alternative

There is also the function chr(...) or even sprintf(...) (or even with printf(...)), for example:

<?php

$caracterChr = chr(27);

$caracterPrintf = sprintf('%c', 27);

var_dump($caracterChr, $caracterPrintf);

Comparing both:

if ($caracterChr === $caracterPrintf) {
    echo 'São iguais';
} else {
    echo 'São diferentes';
}

See the example in ideone: https://ideone.com/FJnGJp