php control statements

8/13/2019 PHP Control Statements

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FEU EAST ASIA COLLEGEInformationTechnologyDepartment

The PHP Control Statements

Conditional StructureRepetitive Structure


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Review on the Language Structure of

PHP

How to start PHP?

Creating and saving your PHP files

PHP Delimeters

Comments in PHP The use of Single and Double Quotations

Variables (scalar and Constant Values

Concatenation symbol !sca"e character and Casting

#"erators ($%$&% &&% ''


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if statement

The ifconstruct is one of the most im"ortant feature of

many languages% including PHP

)t allows for conditional e*ecution of code fragments PHP features an if structure that is similar to that of c

Syntax: if (expression/condition){

statement; }


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Example

Control Statements


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!roup Several Statement

&


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What is "b#

&


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What is "b#

&


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What is "b#

&


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else

elsee*tends an ifstatement to e*ecute astatement in case the e*"ression in theif

statement evaluates to 'S* &

$a !;

$b ";

if($a < $b) {

echo #a is bier than b%;

} else { echo #b is smaller than a%;

}


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else if $ elseif

+s its name suggests% is a combination of ifand else

&

$a !;

$b "; if($a > $b) {

echo #a is bier than b%;

} elseif($a < $b) {

echo #a is smaller than b%;

} else {

echo #a and b are e+,al%;


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FEU EAST ASIA COLLEGE

InformationTechnologyDepartment

% tric&' one


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%lternative S'ntax for if

)t is "ossible to write control statementsusing the following ,colon- format.


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(ixing HT(L with PHP Control

Statements

.he condition is tr,e

$i is -

.he condition is false

$i is not -


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switch statement

The switchstatement controls "rogram flow by e*ecutinga s"ecific set of statements% de"ending on the value of an

e*"ression

)t com"ares the value of an e*"ression to a valuecontained within a s"ecial statement called a case label

+ case label in a switch statement re"resents a s"ecificvalue and contains one or more statements that e*ecute if

the value of the case label matches the value of the switch

statement/s e*"ression


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switch statement

Synta* s3itch (expression) {

case label1

statement (s);

brea4; case label1

statement(s);

brea4;

&

defa,lt1

statement(s);

}


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Example


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Example


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Information

TechnologyDepartment

case Labels

case $*xample:ar1 // ariable name

statement(s);

case #text strin%1 // strin literal

statement(s);

case !1 // inteer literal

statement(s);

case =2"1 // floatin=point literal

statement(s);

Case ($time < -@@)1 // conditional expression

statement(s); or operations


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Information


Repeating Code

while Statements )t is one of the sim"lest ty"es of loo"s% which re"eats a

statement or series of statements as long as a givenconditional e*"ression evaluates to true

Synta*.

3hile (conditional expression) {

statement(s);

}


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Information


Example

$Co,nt -;

3hile ($Co,nt


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Information


Example

$Co,nt -@; 3hile ($Co,nt > @) {

echo #$Co,nt
%;

==$Co,nt; }

echo #

Be hae liftoff
%;


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Information


)efine the output

$Co,nt -; 3hile ($Co,nt


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Information


%lternative S'ntax


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Information


do*while Statements

Syntax:

do {

statement(s);

} 3hile (conditional expression);

The do3hilestatement will always e*ecute the bloc0

of code once% it will then chec0 the condition% and re"eat the

loo" while the condition is true


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Information


Example

$Co,nt @;

do {

echo #.he co,nt is e+,al to

$Co,nt
%;

AA$Co,nt;

} 3hile ($Co,nt


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Information


for statement

Synta*.

for(counter declaration and initialization;condition; update statement) {

statement(s);

}

The for loopis used when you 0now in advance how

many times the scri"t should run


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Information

TechnologyDepartment 12

The for loop

+ counting loo" is usually im"lemented with for

for ($i@; $i < $co,nt; $iAA) {

print(7
index al,e is 1 $i7);

}

initiali3e chec0 for limit

u"date loo" control inde*

shorthand for i+i,-

one or more statements in the loo" body


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Information


Example


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Information


brea&

brea0 ends e*ecution of the current for% foreach%while% do4while or switch structure

0123

4


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Information


Example


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Information


continue

continue is used within loo"ing structures to s0i" the restof the current loo" iteration and continue e*ecution at thecondition evaluation and then the beginning of the ne*titeration


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Information


printinside forstatement


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Laborator' %ctivit'

Create a PHP "rogram that will ma0e useof a day in a wee0 to change the

bac0ground color of your web "age as well

as its te*t color 6ou may use all the controlstatements discussed in PHP

W b P i


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Information

Technology

Short .ui/ 0

1. What is $x, assuming that itsinitial value is 10 (3 pts)if($x>) {

if($x) {

if ($x "!){

$fee 2@@@;

}elseif($speed > !@){

$fee @@@;

}elseif($speed > !){

$fee D@@@;

}

echo $fee;

php control statements

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