[SYMBOL]
[A]
[B]
[C]
[D]
[E]
[F]
[G]
[H]
[I]
[J]
[K]
[L]
[M]
[N]
[O]
[P]
[Q]
[R]
[S]
[T]
[U]
[V]
[W]
[X]
[Z]
/ (forward slash) division operator
. (period) string concatenation operator
2nd
!= not-equal operator
# (hash mark), comments in PHP programs
$ (dollar sign) anchor
$_COOKIE auto-global array
$_FILES auto-global array
$_GET auto-global array
$_POST auto-global array
2nd
3rd
changing values in
default values for forms, displaying
encrypted passwords and
hidden parameters in
validating numeric and string elements
$_SERVER auto-global array
elements in
$_SESSION auto-global array
saving form data in a session
unset( ) and
$GLOBALS array
$php_errormsg global variable
% (percent sign) modulus division operator
2nd
SQL wildcard
& (ampersand) logical AND operator
&& (two ampersands) logical AND operator
& (ampersand) HTML entity
> (greater than) HTML entity
< (less than) HTML entity
" (double quote) HTML entity
> (greater than) comparing numbers and strings
WHERE clause operator
>= (greater than or equal to) comparing numbers and strings
WHERE clause operator
< (less than) comparing numbers and strings
WHERE clause operator
<<< (here document syntax)
<= (less than or equal to) comparing numbers and strings
WHERE clause operator
<? start tags
2nd
<?php start tags
2nd
3rd
4th
<[ ]> (not equal to) WHERE clause operator
<select> menu
displaying in show_form( )
multiple menus for date input
for time input
processing date/time input from forms
setting default values in
single menu with one choice
( ) (parentheses) grouping characters together in regular expressions
WHERE clause operator
(semicolon), ending PHP programs
* (asterisk) multiplication operator
regular expression quantifier
/* and */ (multiline comments in PHP programs)
+ (plus sign) addition operator
modifier for formatting strings
regular expression quantifier
++ (plus signs) incrementing operator
+= (plus equal), combined assignment and addition operators
- (minus sign) modifier for formatting strings
subtraction operator
- - (minus signs) decrementing operator
-> (arrow) operator
. (period) string concatenation operator truth values and
.. (two dots) filename special sequence
.= (dot equal), combined assignment and string concatenation operators
// (forward slashes), indicating comments in PHP programs
2nd
3rd
= (equal sign) assignment operator assigning return values to variables
assigning values to variables
combining with arithmetic and string operators
with function call in test expression
truth values and
vs. equality operator (==)
WHERE clause operator
= = = (three equal signs) identical operator
=> key/value pair separator
== (two equal signs) equality operator
comparing two strings
vs. assignment operator (=)
? (question mark) quantifier
turning quantifiers from greedy to nongreedy
?> end tags
2nd
3rd
[ ] (square brackets) creating character classes
[[ ]] (square brackets) adding array elements with empty brackets
creating arrays
creating multidimensional arrays
multiple values in form elements
\ (backslash) escape character
2nd
\$ special character
\\ (backslashes) special character
\0 .. \777 special characters
\Ó special character
\x0 .. \xff special characters
^ (caret) anchor
_ (underscore) SQL wildcard
{ } (curly brackets) quantifier
| (bar) alternation metacharacter
logical EITHER/OR operator
|| (two bars) logical OR operator
~ (tilde) logical NOT operator
|