02 Php Vars Op Control Etc

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Day 2Day 2 PHP PHP

Geshan ManandharGeshan ManandharDeveloper, Developer,

Young Innovations Pvt. LimitedYoung Innovations Pvt. Limitedwww.geshanmanandhar.comwww.geshanmanandhar.com

http://www.php.net


Variables in PHPVariables in PHP

►Boolean: It can be either Boolean: It can be either TRUETRUE or or FALSEFALSE. . ► Integer: The size of an integer is platform-Integer: The size of an integer is platform-

dependent, although a maximum value of dependent, although a maximum value of about two billion is the usual value.about two billion is the usual value.

►Float: The size of a float is platform-Float: The size of a float is platform-dependent, although a maximum of dependent, although a maximum of ~1.8e308 with a precision of roughly 14 ~1.8e308 with a precision of roughly 14 decimal digits is a common value decimal digits is a common value


Variable in PHPVariable in PHP

►String: A string is series of characters. String: A string is series of characters. In PHP, a character is the same as a In PHP, a character is the same as a byte, that is, there are exactly 256 byte, that is, there are exactly 256 different characters possible. different characters possible.

►Array: An array in PHP is actually an Array: An array in PHP is actually an ordered map. A map is a type that ordered map. A map is a type that maps maps valuesvalues to to keyskeys. . $names[1] = “Ram”;$names[1] = “Ram”; $names[2] = “Shyam”;$names[2] = “Shyam”;

Variables in PHPVariables in PHP

►Objects: mainly have attributes and Objects: mainly have attributes and functions.functions.

<?php<?phpclass testclass test{{ function do_test()function do_test() {{ echo "Testing class function."; echo "Testing class function."; }}}}

$an_object = new test;$an_object = new test;$an_object->do_test();$an_object->do_test();

?> ?>


Naming variables in PHPNaming variables in PHP

►Variables in PHP are represented by a Variables in PHP are represented by a dollar sign followed by the name of the dollar sign followed by the name of the variable. The variable name is case-variable. The variable name is case-sensitive. sensitive.

►A valid variable name starts with a letter A valid variable name starts with a letter or underscore, followed by any number or underscore, followed by any number of letters, numbers, or underscores. of letters, numbers, or underscores. $a_5=10; //valid$a_5=10; //valid $#b = 20; //invalid$#b = 20; //invalid

►Predefined Variables ($_SERVER, $_POST)Predefined Variables ($_SERVER, $_POST)

ConstantConstant

► You can define a constant by using the define() -You can define a constant by using the define() -function. Once a constant is defined, it can never be function. Once a constant is defined, it can never be changed or undefined. changed or undefined.

<?php<?phpdefine("PI", 3.1415); //defining a constant called PIdefine("PI", 3.1415); //defining a constant called PI

$r=5; //r for radius$r=5; //r for radius$area = PI*$r*$r; //area calculation of circle$area = PI*$r*$r; //area calculation of circle

print "Areas of circle with radius $r is ".$area.".";print "Areas of circle with radius $r is ".$area.".";//user number_format() yourself.//user number_format() yourself.?>?>


Arithmetic OperatorsArithmetic Operators

See Program for more clarification: Day02\prog06_Operators.php


Comparison OperatorsComparison Operators

See code of Day02\prog08_comparision_operators.php


Increment Decrement Increment Decrement OperatorsOperators

► ++ and --++ and --

Code at Day02\prog09_inc_dec_operator.php


Logical OperatorLogical Operator

String OperatorString Operator

► . used to concatenate strings. used to concatenate strings► .= used to append a string..= used to append a string.

<?php<?php$b = ”Hello” . "World!"; // now $b contains "$b = ”Hello” . "World!"; // now $b contains "Hello World!"Hello World!"

$a = "Hello ";$a = "Hello ";$a .= "World!"; // now $a contains "Hello W$a .= "World!"; // now $a contains "Hello World!"orld!"?> ?>

If-else if- elseIf-else if- else

<?php<?php$a=10;$a=10;$b=17;$b=17;

if ($a > $b) {if ($a > $b) { echo "a is bigger than b";echo "a is bigger than b";} elseif ($a == $b) {} elseif ($a == $b) { echo "a is equal to b";echo "a is equal to b";} else {} else { echo "a is smaller than b";echo "a is smaller than b";}}?> ?>

If-else if- else alternateIf-else if- else alternate

<?php<?php$a=10;$a=10;$b=17;$b=17;

if ($a > $b) :if ($a > $b) : echo "a is bigger than b";echo "a is bigger than b"; elseif ($a == $b) :elseif ($a == $b) : echo "a is equal to b";echo "a is equal to b";else :else : echo "a is smaller than b";echo "a is smaller than b";endif;endif;?> ?>

Switch ExampleSwitch Example

<?php<?php$engDay =date ("l");$engDay =date ("l");switch ($engDay)switch ($engDay){{

case "Friday";case "Friday";print "Thank god its Friday";print "Thank god its Friday";

break;break;case "Saturday";case "Saturday";

print "Oh its week end Saturday";print "Oh its week end Saturday";break;break;default: default:

print "Its just another working day of the week.";print "Its just another working day of the week.";}}?>?>

While LoopWhile Loop

<?php<?php$i = 1;$i = 1;while ($i <= 10) {while ($i <= 10) { echo $i++; echo $i++; }}

/* example 2 Alternative syntax*//* example 2 Alternative syntax*/$i = 1;$i = 1;while while ($i <= 10):($i <= 10): echo $i;echo $i; $i++;$i++;endwhile;endwhile;?> ?>

Do While LoopDo While Loop

<?php<?php$i = 0;$i = 0;do {do { echo $i; echo $i;} while ($i > 0);} while ($i > 0);?> ?>

For LoopFor Loop

<?php<?phpfor ($i = 1; $i <= 10; $i++) {for ($i = 1; $i <= 10; $i++) { echo $i;echo $i;}}

/*Alternate for Syntax *//*Alternate for Syntax */for($i = 0; $i <= 10; $i++):for($i = 0; $i <= 10; $i++):

echo "--".$i;echo "--".$i;endfor;endfor;?> ?>

For Each loopFor Each loop

<?php<?php$arr = array("zero" , "one" , "two" , "three" , "four" );$arr = array("zero" , "one" , "two" , "three" , "four" );/*For each example 1 *//*For each example 1 */foreach ( $arr as $value ){foreach ( $arr as $value ){

print " ".$value;print " ".$value;}}print " ";print " ";/*For each example 2 *//*For each example 2 */foreach ( $arr as $key => $value) {foreach ( $arr as $key => $value) {

print " At key ".$key." of the array, the value is print " At key ".$key." of the array, the value is ".$value;".$value;

}}?> ?>

PHP simple FunctionPHP simple Function

<?php<?phpfunction adder($var1, function adder($var1,

$var2){$var2){$sum = $var1+$var2;$sum = $var1+$var2;return $sum;return $sum;

}}?> ?> <html><html><head><head><title>Function with PHP <title>Function with PHP

an example</title>an example</title></head></head>

<body><body><?php<?php$a=10;$a=10;$b=15;$b=15;$added = adder($a, $b);$added = adder($a, $b);?>?>The sum of <?=$a?> and The sum of <?=$a?> and

<?=$b?> is <?<?=$b?> is <?=$added?>.=$added?>.

</body></body></html></html>


Lets get rollingLets get rolling

►Write a program that performs all Write a program that performs all arithmetic operations with 3 variables.arithmetic operations with 3 variables.

► Get the month with date(“F”) function Get the month with date(“F”) function and if its December and day date(“d”) is and if its December and day date(“d”) is greater than 20 and less than 26, print greater than 20 and less than 26, print “Merry Christmas”. “Merry Christmas”.

►Print multiplication table of 5 with for Print multiplication table of 5 with for loop.loop.

►Use foreach loop for an array called Use foreach loop for an array called names and print the names in the array names and print the names in the array with its keys.with its keys.


Questions are welcomeQuestions are welcome

► That’s why god gave us two eyes, two ears That’s why god gave us two eyes, two ears but only one mouth.but only one mouth.

02 Php Vars Op Control Etc

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