002-1 Programming Basics

8/9/2019 002-1 Programming Basics

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WEB202D

WebEngineeringPROGRAMMING BASICS

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Recap◦Static Vs D!na"ic Website#

◦Webser$er% Br&'ser% ())P*())PS#

◦Ser$er+si,e -ang.age $s C/ient+si,e -ang.age#

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O.t/ineoC&""entso Variab/e

o C&nstant

o Data t!pe

o Operat&rs an, epressi&ns

o /&' c&ntr&/ .ncti&n

o .ncti&no Arra!

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St&p44444555o Pr&p&sa/ s.b"issi&n ,ea,/ine6 7 Septe"ber 2018

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C&""entso Comment is .se, &r .n,erstan,ing t9e c&,ing '9i/e t9e c&,es is g&ing t&gr&'

o C&""ent:s;6 a pieces & c&,e t9at t9e P(P parser ign&res

oOne-line comment 6 en, at t9e en, & /ine ** &r Na"[email protected]'a!

#

oMulti-line comments 6 "&re t9an &ne /ine * *

oEa"p/e6 * )9is is a c&""ent &n 4

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Variab/eo Variable 6 a /&cati&n &r st&ring a piece & ,ata in "e"&r!oWe are g&ing t& "anip./ate t9e" in &.r pr&gra"s

oR./es re/ate, t& $ariab/es6

oM.st start 'it9 > sign

oCase sensiti$e

o )!pe /ess

oCan inc/.,e /etters% n."bers an, .n,ersc&re :F; c9aracter% b.t n& space

oNa"e ".st begin 'it9 .n,ersc&re &r /etter

oNa"e & $ariab/e s9&./, be "eaning./ :>na"e ? @23 >na"e ? @&9n;

oEa"p/e6 in, t9e c&rrect &ne:s;# C&./, !&. c&rrect t9e"#

o FNa"e?@&9n >20a"i/!na"e?@&9ns&n >F.ni$ersit!na"e?S.n'a!

o>A,,ress ?@Peta/ing a!a >F,.e ,ate?@2018

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C&nstanto )9e $a/.e is re"aine, .nc9ange,oDene:@c&nstantna"e%c&nstant $a/.e;

oEa"p/e 6

Dene:@Jni$ersit!na"e% S.n'a! Jni$ersit!;

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Data t!peo Again% P(P is t!pe /ess55 B! ,ea./t is ,&.b/e

oChanging type6 p.t na"e & ,ata t!pe in r&nt & $ariab/ebet'een parent9eses

o

Ea"p/e6>Age?@13H ** ,&.b/e 13H

Ec9& gett!pe:>Age; **D&.b/e

>Age?integer:>Age; **Integer 13

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Operat&rs an,

epressi&nso Operators are s!"b&/s t9at "aLe t9is p&ssibi/it! t& "aLe ne'$a/.e

o Operand is a $a/.e .se, in c&n.ncti&n 'it9 &perat&r

o Ea"p/e6 '9ic9 &ne is &peran, an, &perat&rs#

8

o Expression is a combination & &peran,s an, &perat&rs t&"aLe t9e res./t

o Assignment operator 6 taLes t9e $a/.e & its rig9t+9an,&peran, an, assigns it t& its /et+9an, &peran,

o Ea"p/e 6

>na"e?@&9n


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Operat&rs an,

epressi&nso Arithmetic operators6 ,& arit9"etic &perati&ns &n&peran,s

oConcatenation operator 6 a sing/e ,&t :; '9ic9 is

.sing &r b&t9 string &peran,s t& &in t9e"

o Ea"p/e6

Ec9& @)9is is a test

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Operat&rs an,

epressi&nso Incrementing and decrementing 6 t& increase &r,ecrease t9e integer a.t&"atica//!% especia//! in iterati&n

Ea"p/e6>?

>?> **Incre"ent

>?>++ **Decre"ent

&r

> **Incre"ent

++> **Decre"ent

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Operat&rs an,

epressi&nso Comparison operators 6 t& per&r" test &n &peran,soRet.rn t9e B&&/ean $a/.e

oJse./ &r c&ntr&/ str.ct.re s.c9 as I an, '9i/e

state"ent

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/&' c&ntr&/ .ncti&no Wit9&.t fow control &pti&n% 'e &.r script c&./, n&t ."p :n&Qeibi/it!;

oScripts are e$a/.ate, t9eir c&n,iti&ns an, c9ange t9eir be9a$i&rs:,!na"ic;

o

I statement 6 e$a/.ates t9e epressi&n bet'een parent9eses I t9eres./t is tr.e% t9e state"ent is eec.te Ot9er'ise% t9e state"ent issLippe,

Ea"p/e6

>M&nt9?

i :>M&nt9 ?? 12 ;

ec9& Tes% t9atUs tr.e55

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/&' c&ntr&/ .ncti&no Else6 a/ternati$e b/&cL & c&,e t9at s9&./, be eec.te,i t9e epressi&n res./t is a/se

o Ea"p/e6

>-.nc9?@C9icLenI :>-.nc9 ?? @Rice;

Ec9& @N&t ba,

e/se

Ec9& @Its great555

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/&' c&ntr&/ .ncti&no Else i 6 t& e$a/.ate "./tip/e epressi&ns be&re ."ping t& t9e,ea./t b/&cL & c&,e

o Ea"p/e6

>-.nc9?@C9icLen

I :>-.nc9 ?? @Rice; ** irst epressi&n e$a/.ati&n

Ec9& @N&t ba,

e/se i :>-.nc9 ?? @is9; ** Sec&n, epressi&n e$a/.ati&n

Ec9& @Its great555

e/se **,ea./t b/&cL & c&,e

Ec9& @A'es&"e

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/&' c&ntr&/ .ncti&no witch statement 6 A/ternati$e 'a! & c9anging t9eQ&' b! e$a/.ating t9e epressi&n

o

On/! &ne epressi&n is e$a/.ate, in s'itc9 state"entb.t eec.ting ,ierent c&,es% acc&r,ing t& t9e res./t

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/&' c&ntr&/ .ncti&noEa"p/e 6>M&&, ? sa,

s'itc9 :>M&&,;

case 9app! 6

ec9& G&&, "&&,

breaL

case sa,6

ec9& Ba, "&&,

breaL

,ea./t6

ec9& Neit9er 9app! &r sa,

breaL

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/&' c&ntr&/ .ncti&no !oops 6 t& eec.te t9e b/&cL & c&,es &r se$era/ ti"eso "hile statement 6 eec.te t9e c&,e b/&cL '9i/e t9e epressi&n$a/.e is tr.e

o Iteration 6 eac9 eec.ti&n & c&,e b/&cL 'it9in /&&p

o Wit9in t9e c&,e b/&cL% s&"et9ing is c9ange, t9at aects &n t9e'9i/e epressi&n :n& c9anging ? "aLing innite /&&p% s& be care./;

o Ea"p/e6

>N."ber?1

'9i/e :>N."ber=?20; **E$a/.ati&n in t9e beginning ec9& >N."ber

>N."ber **C9ange t9e epressi&n $a/.e

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/&' c&ntr&/ .ncti&no#o $$ while statement 6 epressi&n is e$a/.ate, at t9een,

o C&,e b/&cL is eec.te, at /east &nce

o

Ea"p/e6>N."ber?1

D&

ec9& >N."ber **Eec.te &nce

>N."ber **C9ange t9e epressi&n $a/.e

W9i/e :>N."ber=?20; **E$a/.ati&n at t9e en,

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/&' c&ntr&/ .ncti&no&rea'ing out o loops ( c&./, breaL &.t base, &n t9e res./ts& a,,iti&na/ test

o Ea"p/e6

>C&.nter ? +8

&r :C&.nter=?20>C&.nter;

i :>C&.nter??0;

breaL ** st&p 9ere '9i/e reac9 t& Xer&

e/se

>ec9& 100*>C&.nter

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/&' c&ntr&/ .ncti&no'ipping an iteration with continue statement( &pp&site& breaL state"ent

oIgn&re t9e err&r

oEa"p/e6

>C&.nter ? +8

&r :C&.nter=?20>C&.nter;

i :>C&.nter??0;

c&ntin.e ** Ne$er st&p

>ec9& 100*>C&.nter

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.ncti&no %unction ( "aLes t9e c&,e eas! t& re.seo Decrease s&"e repetiti$e '&rLs

oIts /iLe a "ac9ine

o Inp.t is a ra' "ateria/ :$a/.e; an, t9en it '&rLs:pr&cess; &n t9e" t& pr&,.ce t9e pr&,.ct :ne' $a/.e;

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.ncti&no A .ncti&n s9&./, be ca//e, 'it9in !&.r scripto )9e $a/.e is passe, t& t9e .ncti&n

o W9en pr&cessing is nis9e,% a .ncti&n c&./, pass a $a/.e bacL t&t9e ca//ing c&,e

o )ypes o unction 6

o B.i/t+in 6 a$ai/ab/e in P(P /ang.age

oJser+,ene, 6 ,ene b! .ser

o &uilt-in %unction 6 c&./, be ca//e, b! its na"e an, t9e its inp.t

bet'een parent9eses oArgument 6 t9e inp.t t9at is passe, t& t9e .ncti&n

o Ea"p/e6

o print :@(e//& W&r/,; ** (e//& '&r/, is arg."ent

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.ncti&no *ser-de+ned unction 6 is ,ene, b! .sero Ea"p/e6

.ncti&n 'e/c&"e:; ** ,ening .ncti&n 'it9&.t arg."ent

ec9& (e//&

'e/c&"e:;

.ncti&n test.ncti&n:>tet; ,ening .ncti&n 'it9 arg."ent

ec9& @>test

)est.ncti&n:@We/c&"e t& S.n'a! .ni$ersit!; ** .ncti&n na"e is n&t casesensiti$e

test.ncti&n :@(ere is Peta/ing a!a;

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.ncti&no ,eturn statement 6 st&ps eec.ting & t9e .ncti&n an, sen,s t9e $a/.e bacL t& t9eca//ing c&,eolobal .ariable6 accessing &t9er $ariab/e 'it9in t9e script Jsing g/&ba/ be&re $ariab/ena"e

o Ea"p/e6

o>test.ncti&n ? 20

.ncti&n a,,n."ber:>rstn."ber%>sec&n,n."ber%>t9ir,n."ber?20; ** )9irs arg."ent'it9 ,ea./t $a/.e

g/&ba/ >test.ncti&n ** Accessing $ariab/e t9at is ,ene, s&"e'9ere

>res./t ? >rstn."ber >sec&n,n."ber >t9ir,n."ber

>res./t2 ? >test.ncti&n 2

ret.rn >res./t ** Ret.rn 0

a,,n."ber:10%20; ** N& t9ir, arg."ent

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.ncti&noExample (

.ncti&n a,,n."ber:>rstn."ber;

>rsn."ber ? ** >rstn."ber ? >rstn."ber

>test ? 2

A,,n."ber:>test;

Ec9&test ** 2

oExample (

.ncti&n a,,n."ber:Y>rstn."ber; ** Pass an arg."ent t& .ncti&n b! reerence

>rsn."ber ? **

>rstn."ber ? >rstn."ber

>test ? 2

A,,n."ber:>test;

Ec9&test ** 30

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Arra!o Variab/e st&res &n/! &ne $a/.e at a ti"eo Array ( specia/ t!pes & $ariab/e t9at enab/es !&. t& st&re as "an!$a/.es as !&. 'ant

o

Its in,ee, 'it9 a Le! :p&siti&n r&" 0; an, $a/.eo Ea"p/e6 ).es,a!

o>,a!s ?arra!:M&n,a!%).es,a!%We,nes,a!%)9.rs,a!%ri,a!%Sat.r,a!%S.n,a!;

>,a!sZ0[?\]M&n,a! ** An&t9er 'a! t& ,ene arra!

>,a!sZ3[?@).es,a!

>,a!s Z[ ? @test ** Wi// be a,,e, t& t9e en, & t9e arra!

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Arra!o Associate 'ey 6 instea, & .sing ,ea./t Le! :0%1%2%;% 'e c&./,.se ,ene, Le!

o Ea"p/e6

>st.,ent ? arra!:na"e?&9n% /astna"e?"a%

Age?30;

ec9& >st.,entZ\Age][

Print >st.,entZ\/astna"e][

>st.,entZ\ICn."ber][ ? 1238HK7 ** t& a,,

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002-1 Programming Basics