Strings in PHP

Single vs double quotes

Single quotes print text exactly, double quotes interpolate variables and read escape sequences like newline:

echo "First\nSecond"; // two lines echo 'No \n here'; // prints \n as text

Concatenation with dot

The dot glues strings together. Surround it with spaces so the line stays readable:

$first = "Ada"; $last = "Lovelace"; $full = $first . " " . $last; echo $full; // Ada Lovelace

Heredoc and nowdoc

Long texts read better as heredoc: an opening marker, plain lines, and the same marker at the start of the closing line. Variables still interpolate inside:

$name = "Ada"; $text = <<<TEXT Hello, $name! Welcome back. TEXT; echo $text;

Nowdoc uses the same shape with a quoted marker and never interpolates, which fits samples with dollar signs:

$sample = <<<'TEXT' Price: $5, no variables here. TEXT; echo $sample;

Length and access by offset

strlen counts bytes, and square brackets read one byte by its offset starting from zero:

$word = "PHP"; var_dump(strlen($word)); // int(3) echo $word[0]; // P echo $word[2]; // P

For alphabets beyond ASCII use mb_strlen, because strlen counts bytes and not characters.

Next: Numbers in PHP

Автор статьи: Arthur Isaev