Data types

1
Data types

• Fundamental data types
• Integer, floating point, character
• Derived data types
• Arrays
• Strings
• Structures

2
Fundamental data types

• Integer types
• short, int, long
• Character type
• char
• Boolian type
• bool
• Floating-point types
• float, double, long double

3
Integer limits
4
Integer limits

• // limits.cpp -- some integer limits
• include ltiostreamgt
• using namespace std
• include ltclimitsgt // use limits.h for older
  systems
• int main()
• int n_int INT_MAX // initialize
  n_int to max int value
• short n_short SHRT_MAX // symbols
  defined in limits.h file
• long n_long LONG_MAX
• // sizeof operator yields size of type or of
  variable
• cout ltlt "int is " ltlt sizeof (int) ltlt "
  bytes.\n"
• cout ltlt "short is " ltlt sizeof n_short ltlt "
  bytes.\n"
• cout ltlt "long is " ltlt sizeof n_long ltlt "
  bytes.\n\n"
• cout ltlt "Maximum values\n"
• cout ltlt "int " ltlt n_int ltlt "\n"
• cout ltlt "short " ltlt n_short ltlt "\n"

5
Exceeding integer limits

• // exceed.cpp -- exceeding some integer limits
• include ltiostreamgt
• using namespace std
• define ZERO 0 // makes ZERO symbol for 0
  value
• include ltclimitsgt // defines INT_MAX as largest
  int value
• int main()
• short sam SHRT_MAX // initialize a
  variable to max value
• unsigned short sue sam// okay if variable
  sam already defined
• cout ltlt "Sam has " ltlt sam ltlt " dollars and
  Sue has " ltlt sue
• cout ltlt " dollars deposited.\nAdd 1 to each
  account.\nNow "
• sam sam 1
• sue sue 1
• cout ltlt "Sam has " ltlt sam ltlt " dollars and
  Sue has " ltlt sue
• cout ltlt " dollars deposited.\nPoor Sam!\n"
• sam ZERO
• sue ZERO
• cout ltlt "Sam has " ltlt sam ltlt " dollars and
  Sue has " ltlt sue

6
Arithmetic

• // arith.cpp -- some C arithmetic
• include ltiostreamgt
• using namespace std
• int main()
• cout.setf(ios_basefixed, ios_basefloatfiel
  d) // fixed-point
• float hats, heads
• cout ltlt "Enter a number "
• cin gtgt hats
• cout ltlt "Enter another number "
• cin gtgt heads
• cout ltlt "hats " ltlt hats ltlt " heads " ltlt
  heads ltlt "\n"
• cout ltlt "hats heads " ltlt hats heads ltlt
  "\n"
• cout ltlt "hats - heads " ltlt hats - heads ltlt
  "\n"
• cout ltlt "hats heads " ltlt hats heads ltlt
  "\n"
• cout ltlt "hats / heads " ltlt hats / heads ltlt
  "\n"
• return 0

7
Character variables

• // chartype.cpp -- the char type
• include ltiostreamgt
• using namespace std
• int main( )
• char ch // declare a char variable
• cout ltlt "Enter a character\n"
• cin gtgt ch
• cout ltlt "Holla! "
• cout ltlt "Thank you for the " ltlt ch ltlt "
  character.\n"
• return 0

8
Type cast

• // typecast.cpp -- forcing type changes
• include ltiostreamgt
• using namespace std
• int main()
• int auks, bats, coots
• // the following statement adds the values as
  double,
• // then converts the result to int
• auks 19.99 11.99
• // these statements add values as int
• bats (int) 19.99 (int) 11.99 // old C
  syntax
• coots int (19.99) int (11.99) // new
  C syntax
• cout ltlt "auks " ltlt auks ltlt ", bats " ltlt
  bats
• cout ltlt ", coots " ltlt coots ltlt '\n'
• char ch 'Z'
• cout ltlt "The code for " ltlt ch ltlt " is "
  // print as char

9
Derived data types

• Arrays
• static, dynamic
• Strings
• Structures

10
Arrays

• // arrayone.cpp _ small arrays of integers
• include ltiostreamgt
• using namespace std
• int main()
• int yams3 // creates array with three
  elements
• yams0 7 // assign value to first
  element
• yams1 8
• yams2 6
• int yamcosts3 20, 30, 5 // create,
  initialize array
• // NOTE If your C compiler or translator can't
  initialize
• // this array, use static int yamcosts3 instead
  of
• // int yamcosts3
• cout ltlt "Total yams "
• cout ltlt yams0 yams1 yams2 ltlt "\n"
• cout ltlt "The package with " ltlt yams1 ltlt "
  yams costs "

11
Strings

• // strings.cpp _ storing strings in an array
• include ltiostreamgt
• include ltcstringgt // for the strlen() function
• using namespace std
• int main()
• const int Size 15
• char name1Size // empty
  array
• char name2Size "Cowboy" //
  initialized array
• // NOTE some implementations may require the
  static keyword
• // to initialize the array name2
• cout ltlt "Howdy! I'm " ltlt name2
• cout ltlt "! What's your name?\n"
• cin gtgt name1
• cout ltlt "Well, " ltlt name1 ltlt ", your name has
  "
• cout ltlt strlen(name1) ltlt " letters and is
  stored\n"

12
Strings
13
Structures
14
Structures

• // structur.cpp -- a simple structure
• include ltiostreamgt
• using namespace std
• struct inflatable // structure template
• char name20
• float volume
• double price
• int main()
• inflatable guest
• "Glorious Gloria", // name value
• 1.88, // volume value
• 29.99 // price value
• // guest is a structure variable of type
  inflatable
• // It's initialized to the indicated values

• inflatable pal
• "Audacious Arthur",
• 3.12,
• 32.99
• // pal is a second variable of type
  inflatable
• // NOTE some implementations require using
• // static inflatable guest
• cout ltlt "Expand your guest list with " ltlt
  guest.name
• cout ltlt " and " ltlt pal.name ltlt "!\n"
• // pal.name is the name member of the pal
  variable
• cout ltlt "You can have both for "
• cout ltlt guest.price pal.price ltlt "!\n"
• return 0

15
Assigning structures

• // assgn_st.cpp -- assigning structures
• include ltiostreamgt
• using namespace std
• struct inflatable
• char name20
• float volume
• double price
• int main()
• inflatable bouquet
• "sunflowers",
• 0.20,
• 12.49
• inflatable choice

16
Local and external declarations