Data types

• Fundamental data types– Integer, floating point, character

• Derived data types– Arrays

– Strings

– Structures

Fundamental data types

• Integer types– short, int, long

• Character type– char

• Boolian type– bool

• Floating-point types– float, double, long double

Integer limits

Integer limits

// limits.cpp -- some integer limits#include <iostream>using namespace std;#include <climits> // use limits.h for older systemsint 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 << "int is " << sizeof (int) << " bytes.\n";

cout << "short is " << sizeof n_short << " bytes.\n"; cout << "long is " << sizeof n_long << " bytes.\n\n";

cout << "Maximum values:\n"; cout << "int: " << n_int << "\n"; cout << "short: " << n_short << "\n"; cout << "long: " << n_long << "\n\n";

cout << "Minimum int value = " << INT_MIN << "\n"; return 0;}

Exceeding integer limits// exceed.cpp -- exceeding some integer limits#include <iostream>using namespace std;#define ZERO 0 // makes ZERO symbol for 0 value#include <climits> // defines INT_MAX as largest int valueint main(){ short sam = SHRT_MAX; // initialize a variable to max value unsigned short sue = sam;// okay if variable sam already defined

cout << "Sam has " << sam << " dollars and Sue has " << sue; cout << " dollars deposited.\nAdd $1 to each account.\nNow "; sam = sam + 1; sue = sue + 1; cout << "Sam has " << sam << " dollars and Sue has " << sue; cout << " dollars deposited.\nPoor Sam!\n"; sam = ZERO; sue = ZERO; cout << "Sam has " << sam << " dollars and Sue has " << sue; cout << " dollars deposited.\n"; cout << "Take $1 from each account.\nNow "; sam = sam - 1; sue = sue - 1; cout << "Sam has " << sam << " dollars and Sue has " << sue; cout << " dollars deposited.\nLucky Sue!\n"; return 0}

Arithmetic// arith.cpp -- some C++ arithmetic#include <iostream>using namespace std;int main(){ cout.setf(ios_base::fixed, ios_base::floatfield); // fixed-point float hats, heads;

cout << "Enter a number: "; cin >> hats; cout << "Enter another number: "; cin >> heads;

cout << "hats = " << hats << "; heads = " << heads << "\n"; cout << "hats + heads = " << hats + heads << "\n"; cout << "hats - heads = " << hats - heads << "\n"; cout << "hats * heads = " << hats * heads << "\n"; cout << "hats / heads = " << hats / heads << "\n";

return 0;}

Character variables// chartype.cpp -- the char type

#include <iostream>

using namespace std;

int main( )

{

char ch; // declare a char variable

cout << "Enter a character:\n";

cin >> ch;

cout << "Holla! ";

cout << "Thank you for the " << ch << " character.\n";

return 0;

}

Type cast// typecast.cpp -- forcing type changes#include <iostream>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 << "auks = " << auks << ", bats = " << bats; cout << ", coots = " << coots << '\n';

char ch = 'Z'; cout << "The code for " << ch << " is "; // print as char cout << int(ch) << '\n'; // print as int return 0;}

Derived data types

• Arrays– static, dynamic

• Strings• Structures

Arrays

// arrayone.cpp _ small arrays of integers#include <iostream>using namespace std;int main(){ int yams[3]; // creates array with three elements yams[0] = 7; // assign value to first element yams[1] = 8; yams[2] = 6;

int yamcosts[3] = {20, 30, 5}; // create, initialize array// NOTE: If your C++ compiler or translator can't initialize // this array, use static int yamcosts[3] instead of // int yamcosts[3]

cout << "Total yams = "; cout << yams[0] + yams[1] + yams[2] << "\n"; cout << "The package with " << yams[1] << " yams costs "; cout << yamcosts[1] << " cents per yam.\n"; int total = yams[0] * yamcosts[0] + yams[1] * yamcosts[1]; total = total + yams[2] * yamcosts[2]; cout << "The total yam expense is " << total << " cents.\n";

cout << "\nSize of yams array = " << sizeof yams; cout << " bytes.\n"; cout << "Size of one element = " << sizeof yams[0]; cout << " bytes.\n"; return 0;}

Strings

// strings.cpp _ storing strings in an array#include <iostream>#include <cstring> // for the strlen() functionusing namespace std;int main(){ const int Size = 15; char name1[Size]; // empty array char name2[Size] = "C++owboy"; // initialized array// NOTE: some implementations may require the static keyword// to initialize the array name2

cout << "Howdy! I'm " << name2; cout << "! What's your name?\n"; cin >> name1; cout << "Well, " << name1 << ", your name has "; cout << strlen(name1) << " letters and is stored\n"; cout << "in an array of " << sizeof name1 << " bytes.\n"; cout << "Your initial is " << name1[0] << ".\n"; name2[3] = '\0'; // null character cout << "Here are the first 3 characters of my name: "; cout << name2 << "\n";

return 0;}

Strings

Structures

Structures// structur.cpp -- a simple structure#include <iostream>using namespace std;struct inflatable // structure template{ char name[20]; 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 << "Expand your guest list with " << guest.name;

cout << " and " << pal.name << "!\n";

// pal.name is the name member of the pal variable

cout << "You can have both for $";

cout << guest.price + pal.price << "!\n";

return 0;

}

Assigning structures

// assgn_st.cpp -- assigning structures#include <iostream>using namespace std;struct inflatable{ char name[20]; float volume; double price;};int main(){ inflatable bouquet = { "sunflowers", 0.20, 12.49 }; inflatable choice; cout << "bouquet: " << bouquet.name << " for $"; cout << bouquet.price << "\n";

choice = bouquet; // assign one structure to another cout << "choice: " << choice.name << " for $"; cout << choice.price << "\n"; return 0;}

Local and external declarations