STRING


string apg

Any simple sequence of characters.

Since PHP 7.0.0, there are no particular restrictions regarding the length of a STRING on 64-bit builds.

On 32-bit builds and in earlier versions, a STRING can be as large as up to 2147483647 bytes maximum.

STRING is a type of variable commonly used in PHP.



<?php

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    
  The name of a variable always starts with a $    
  
  The character next to $ can NEVER be numeric
  
  The characters: _, ç e Ç are allowed
  
  Reserved characters, of course, can not be used
 
  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

?> 

 How are STRINGs recognized? 


Any STRING has its name started by the  $   character and the character next to  $   can NEVER be numeric.


See the tables and exercises with the general rules below:



STRING
GENERAL REPRESENTATION
SIMBOL NAME USE
$ DOLLAR SIGN First character of VARIÁVEL name
$name (*) IDENTIFIES THE VARIABLE Defined by the user
at programming time
= EQUAL Value assignment character
; SEMICOLON MANDATORY character
of termination in code line
(*) The character next to $ can NEVER be NUMERIC.
(*) Characters like: _, ç e Ç are allowed.
(*) Reserved characters, of course, can not be used.
ed48

STRING
EXTENDED SPECIFICATION
STRING TYPE
SINGLE QUOTED ' string ';
DOUBLE QUOTED " string ";
HEREDOC SYNTAX <<<EOT
 string of
multiple lines 
EOT;
NEWDOC SYNTAX <<<'EOD'
 string of
multiple lines 
EOD;"
ed48

STRING
ESCAPED CHARACTER
REPRESENTATION MEANING
\n Linefeed
(LF or 0x0A (10) in ASCII)
\r Carriage return
(CR or 0x0D (13) in ASCII)
\t Horizontal tab
(HT or 0x09 (9) in ASCII)
\v Vertical tab
(VT or 0x0B (11) in ASCII)
(since PHP 5.2.5)
\e Escape
(ESC or 0x1B (27) in ASCII)
(since PHP 5.4.4)
\f Form feed
(FF or 0x0C (12) in ASCII)
(since PHP 5.2.5)
\\ BACKSLASH
\$ DOLLAR SIGN
\' SINGLE-QUOTE
\" DOUBLE-QUOTE
\[0-7]{1,3} The sequence of characters matching the regular expression is a character in octal notation, which silently overflows to fit in a byte
(e.g. "\400" === "\000")
\x[0-9A-Fa-f]{1,2} The sequence of characters matching the regular expression is a character in hexadecimal notation.
\u{[0-9A-Fa-f]+} The sequence of characters matching the regular expression is a Unicode codepoint, which will be output to the string as that codepoint's UTF-8 representation.
(added in PHP 7.0.0)
ed48

  1 EXERCISE   

<?php

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     SOME VALID VARIABLE EXAMPLES
     STRING: USER-DEFINED 

     All VARIABLES after the value assignment
     must end with a SEMICOLON.
  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    
  $xyz = "\"STRING DELIMITED BY DOUBLE QUOTATION MARKS\""; 
   
 $str0 = '\'STRING DELIMITED BY SINGLE QUOTATION MARKS\''; 
  
 $carÇ = '\'STRING DELIMITED BY SINGLE "QUOTATION MARKS"\''; 
  
 $_alo = "\"STRING DELIMITED BY DOUBLE 'QUOTATION MARKS'\""; 
  
 $rquo = "&nbsp;&nbsp;&raquo;&nbsp;&nbsp;"; 
  
$str01a = "1AnVXY234";  
  
$str01b = "1234567";

// HEREDOC
$str01c = <<<EOD
Easy come, easy go.
If you can’t beat them, join them.
Life begins at forty.
Two heads are better than one. 
EOD;

$str01d = <<<EOT
In PHP there are TWO types
of variables:
INTERNAL, (predefined).
OF USER: (user-defined).
EOT;

// NOWDOC
$str01e = <<<'EOD'
Easy come, easy go.
If you can’t beat them, join them.
Life begins at forty.
Two heads are better than one. 
EOD;

$str01f = <<<'EOT'
In PHP there are TWO types
of variables:
INTERNAL, (predefined).
OF USER: (user-defined).
EOT;

?>