PHP Operators

• In programming and logic, an operator symbol is used to perform an operation on some value such as addition, substraction, and so on
• Operators assign values, works with strings and numbers and can control program flow
• Types of operators
  • Assignment
  • Math (Same as when you learned math in grade school)
  • String
  • Comparison
  • Logical

Assignment Operators

• The Assignment Operators ( = ) sets the value to the left of the operand to the value on the right

• You can also combine it with other operators

<?php
//Combined Operators	//Same as
$a=$b;	$a=$b;		//The left operand gets set to the value of the expression on the right
$a+=$b;	$a=$a+$b;	//Addition
$a-=$b;	$a=$a-$b;	//Substraction
$a*=$b;	$a=$a*$b;	//Multiplication
$a/=$b;	$a=$a/$b;	//Division
$a%=$b;	$a=$a%$b;	//Modulus
$a.=$b;	$a=$a.$b;	//Concatenate
?>

Concatenate Operator is Often used to create output
TIP: Do not think of = as "equal" ... think of it as "assignment"
TIP: Think of == as "equal"

Math Operators

• The PHP math/arithmetic operators are used with numeric values to perform common arithmetical operations, such as addition, subtraction, multiplication etc.

Examples	Name	Result
-$a	Negative	Negative Value of $a
$a + $b	Addition	Sum of $a and $b
$a - $b	Substraction	Difference of $a and $b
$a * $b	Multiplication	Product of $a and $b
$a / $b	Division	Quotient of $a and $b
$a % $b	Modulus	Remainder of $a divided by $b
$a ** $b	Exponentiation	Result of raising $a to the $b'th power

TIP: The division operator("/") return a float value anytime, even if the two operands are integers (or strings that get converted to integers)

There are also increment/decrement operators ++ and --

Note: $a++ is equal to $a+1

String Operators

• PHP has two operators that are specially designed for strings.

• The conceatenation operator (.) allows you to combine two strings together into a single string

Examples	Name	Result
$txt1 . $txt2	Concatenation	Concatenation of $txt1 and $txt2
$txt1 .= $txt2	Concatenation assignment	Appends $txt2 to $txt1

for example, both these lines of code have the same result

<?php
	echo "Hello "."World";
	echo "Hello World";
?>

Comparison Operators

• If you compare an integer with a string, the string is converted to a number

• If you compare two numerical strings, they are compared as integers

Examples	Name
$a==$b	equal
$a===$b	Identical (same value and type)
$a!=$b	Not equal
$a<>$b	Not equal (numerical)
$a!==$b	Not Identical (values and types not the same)
$a<$b	Less than
$a>$b	Greater than
$a<=$b	Less than or equal to
$a>=$b	Greater than or equal to
$a <=> $y=b	Spaceship(Returns an integer less than, equal to, or greater than zero, depending on if $a is less than, equal to, or greater than $b. Introduced in PHP 7.)

Note: "Not identical" values and types are not the same

Logical Operators

You are already be femiliar with some of these operators

• and ("and" and && symbols are both supported)
• or ("or" and || symbols are both supported)
• xor ("xor" and ^ symbols are both supported)
• not ("not" and ! symbols are both supported)

Why are two symbols that do same thing?

• Order Precedence -it depends upon which symbol you use
• For Example- and or && - the entire statement may evaluate to a different result
• The reason for the two difference variation of "and" and "or" operators is that they operate at different precedences
• Be sure to define xor: $a xor $b if either is true but not both