ZEND PHP 5 Certification STUDY GUIDE

16 ” PHP Basics
Arithmetic Operators
Arithmetic operators allow you to perform basic mathematical operations:
Addition $a = 1 + 3.5;
Subtraction $a = 4 - 2;
Multiplication $a = 8 * 3;
Division $a = 15 / 5;
Modulus $a = 23 % 7;
i
Do remember that certain arithmetic operators (for example, the addition operator)
assume a different meaning when applied to arrays. You can find more information
on this subject in the Arrays chapter.
Incrementing/decrementing operators are a special category of operators that
make it possible to increment or decrement the value of an integer by one. They
are unary operators, because they only accept one operand (that is, the variable that
needs to be incremented or decremented), and are somewhat of an oddity, in that
their behaviour changes depending on whether they are appended or prepended to
their operand.
The position of the operator determines whether the adjustment it performs takes
place prior to, or after returning the value:
• If the operator is placed after its operand, the interpreter will first return the
value of the latter (unchanged), and then either increment or decrement it by
one.
• If the operator is placed before the operand, the interpreter will first increment
or decrement the value of the latter, and then return the newly-calculated
value.
Here are a few examples:
Licensed to 482634 - Amber Barrow (itsadmin@deakin.edu.au)
$a = 1;
// Assign the integer 1 to $a