PHP-language, conditional
statements
Teppo Räisänen
Principal Lecturer
Oulu University of Applied Sciences
School of Business and Information Management
teppo.raisanen@oamk.fi, 050 382 6587
Control structures
• Conditional structures
– If
– Switch
• Loops
– While
– For
• Functions
• http://us.php.net/manual/en/language.controlstructures.php
Basic syntax
if (expression)
{
...
}
else
{
...
}
Comparison operators
Example
<?
//Read value passed from HTML-form.
$age=$_POST[’age’];
//Found out if user is minor or adult according to age.
if ($age<18)
{
print ”Minor”;
}
else
{
print ”Adult”;
}
?>
Nested statements
<?
$grade=$_POST[’grade’];
If ($grade==0)
{
print ”F”;
}
else
{
if ($grade<3)
{
print ”C”;
}
else
{
if ($grade<5)
{
print ”B”;
}
else
{
if ($gade==5)
{
print ”A”;
}
else
{
print ”Not on scale”;
}
}
}
}
?>
Logical operations
• ||
• &&
• !
OR
AND
NOT
Example
<?
$grade=$_POST[’grade’];
//If grade is not between 0 and 5 it is
//not on scale.
If ($grade<0 || $grade>5)
{
print ”Not on scale”;
}
?>
Switch
• Sometimes you can replace multiple ifstatements with switch statement
• Also logical and comparison operators are
allowed
Exercises
• http://www.oamk.fi/~teraisan/K1053BI/exerci
se.htm
• Exercises 6 to 10 are about conditional
statements