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Calculation with numbers

  1. Aritmetic operations

1. Aritmetic operations

In PHP are 6 simple aritmetic operations. First these are the 4 basic aritmetic operations +, -, * and / (/ is the division as : is already used in php and / is used in any other programming language, too), and there is the unary operator - which negates a number and the operator % which calculate the remains of a division (20:7 = 2 remaining 6).

<?php
$a 
10;
$b 6;
echo 
$a-$b;   // 4
echo $a+$b;   // 16
echo $a*$b;   // 60
echo $a/$b;   // float(1.66666666667)
echo -$a;     // -10, same as echo 0-$a;
echo $a%$b;   // 4 (6 fits one times in 10 with a remain of 4)
?>

For any complex calculaten there exists a lot of functions, to find in the manual at Mathematical Functions. Especially pow is such a function which calculates the exponentation. Beginners try to use ^ as the exponentation and fails as php use ^ for something different than the exponentation (it is used for a bitwise XOR operation).

<?php
$base 
5;
$exponent 7;
echo 
$base^$exponent;        // echos 2, which is not what you want
echo pow($base$exponent);  // echos 78125
?>

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