memory location in c++
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Inside every computer is a componentcalled internal memory.
Computer’s internal memory is composedof memory locations, each with a uniquenumeric address.
Memory location is similar to collection ofstorage bins.
Each address can store one item at a time.
Internal Memory
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Illustration of Storage Bins
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Memory Location
Data Type ' indicates what type ofinformation the address will store %e.g.,
numeric or te!tual&. Identifer ' allows the programmer to
refer to the memory location elsewhere
in the program.' (ames made up by the programmer.
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"ypes of Identi$er
Variables - are memory locations whosevalues can change during runtime %when theprogram is running&. Most memory locationsare variables.
Constants ' are memory locations whosecontent cannot be changed during programe!ecution. )ften named in uppercase letters.
E!ample* PI %constant&, radius %variable&
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+ules In (aming Identi$ers%variables&
(ame must begin with a letter and containonly letters, numbers, and the underscorecharacter
(o punctuation mars, spaces, or other specialcharacters %such as - or & are allowed
Cannot be a eyword %word that has specialmeaning in C//&
(ames are case sensitiveE!ample* discount is di0erent from DISCOUNT andfrom Discount
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1alid or Invalid 1ariables
total2ales
"otal32al4s
"otal 2ales total.2ales
5th6tr2ales total2ale-
"7taLsales
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C// 8eywords
8eywords are prede$ned reservedwords or reserved identi$ers that
have special meanings. "hey cannot be used as identi$ers in
your program
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C// 8eywords
auto
constdouble
9oat
brea
continueelse
for
void
case
default
char
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C// 8eywords
int
shortstruct
endl
long
signedunsigned
e!plicit
do
while
bool
string
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#ata "ypes
Memory locations come in di0erenttypes and si:es
memory location will only accept anitem that matches its data type.
#ata type of a memory location isdetermined by the programmer whendeclaring the location.
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short
int
float double
bool
char string (user-defned data type)
;undamental #ata "ypes in C//
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;undamental #ata "ypes in C//
bool ' stores
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;undamental #ata "ypes in C/
/ oat and double - store real numbers
%numbers with a decimal place&
#i0erences are range of values, precision,and memory used %double has the greaterof each&
char ' stores characters %letter, symbol,or number that will not be used in acalculation& )nly one character stored at a time
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;undamental #ata "ypes in C
/ strin - is a user'de$ned data type,
can store :ero %blan& or more
characters
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;undamental #ata "ypes in C//
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#eclaring Memory Location
>hen declaring a memory location a data type andan identi$er %variable or constant& must be provided
2ynta! for declaring a variable in C//
DataType Identifier ; !"amples#
string age;
float length;
int width;
string lastname;
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ssigning ;loating'point 1aluesto Integer 1ariables
If a 9oating'point value is assigned to aninteger variable "he fractional part will be truncated %i.e.,
?chopped o0@ and discarded& "he value is not rounded
int rainfall = 3.88;cout
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2tring Literals
Can store a series of characters inconsecutive memory locations.
"Hello"
Enclosed in a double quotation " "
Can de$ne string data type in programs string nae;
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char $s strin literal constants
Character literal constants initiali:e char data types Consist of one character in single quotation
mars
2tring literal constants initiali:e string datatypes
Aero or more characters enclosed in doublequotation mars Empty string %“ ”& is a valid string literal
constant.
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+eading in a 2tring 2tatement
' +eads in a string with no blansstring nae;
cin !! nae;
' +eads in a string that may contain blansstring nae;
getlinecin# nae$;
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8nowledge Chec
Identify the data type of the following variables*!astname
PI where PI #$%&%'
( where ( %))
*adius where radius +,
True
width where width %)
-gePhoneNum.er
)
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repared by* rof. L+6 (atividad
Than% & ou''
That in ll Thins od May ,e lori