PHP

PHP is a server side scripting language.

Basic Syntax & Commands

PHP statements are always terminated with semicolon (;).

Single quotes are used to mark start and end of text ()

All variable names in PHP start with dollar sign ($).

PHP is a loosely typed language. Variables may contain any type of data.

Example:

$variable_name = "Semper Fidelis";

Equal sign is called the assignment operator since it assigns values to variables.

Comments begin with // or /* */

arithmetic operators enable you to add, subtract, multiply, & divide.

concatenation operator allows you to add strings of text.

Example:

$variable_name = "Hello" . " there" . " world!";

Assigns value of "Hello there world!" without quotes.

Examples:

variable	comment
$var1 = 'PHP';	Assigns value of "PHP" to var1
$var2 = 5;	Assigns value of 5 to $var2
$var3 = $var2 + 1;	Assigns value of 6 to $var3
$var2 = $var1;	Assigns value of "PHP" to $var2
echo($var1);	Outputs "PHP"
echo($var2);	Outputs "PHP"
echo($var3);	Outputs 6
echo($var1 . ' rules!');	Outputs "PHP rules!"
echo("var1 rules!");	Outputs "PHP rules!"
echo('var1 rules!');	Outputs '$var1 rules!'

NOTE: Double quotes around text enables the variable name to be inserted & value is displayed. This is called variable interpolation Single quotes will not interpolate the variable name.