C++ Tutorial/Data Types/int — различия между версиями
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Текущая версия на 13:31, 25 мая 2010
Содержание
- 1 Calculate the product of three integers
- 2 Calculate the value of product and quotient
- 3 Comparing integers using if statements, relational operators and equality operators.
- 4 constant integer value
- 5 Convert gallons to liters
- 6 Define and assign int variables
- 7 Define an int variable
- 8 Do bit operation on integers: AND, OR, XOR
- 9 Do calculation in cout
- 10 lists cubes from 1 to 10: int type variable calculation
- 11 simple FOR loop controlled by int type variable
- 12 Use arithmetic operator to get the product of two integers
Calculate the product of three integers
<source lang="cpp">#include <iostream> using std::cout; using std::cin; using std::endl; int main() {
int x; int y; int z; int result; cout << "Enter three integers: "; cin >> x >> y >> z; // read three integers from user result = x * y * z; cout << "The product is " << result << endl; return 0;
}</source>
Enter three integers: 1 2 3 The product is 6
Calculate the value of product and quotient
<source lang="cpp">#include <iostream> using std::cout; using std::endl; int main() {
int x = 5; int product = 5; int quotient = 5; product *= x++; cout << product << endl; cout << x << endl << endl; x = 5; quotient /= ++x; cout << quotient << endl; cout << x << endl; return 0;
}</source>
25 6 0 6
Comparing integers using if statements, relational operators and equality operators.
<source lang="cpp">#include <iostream> using std::cout; using std::cin; using std::endl; int main() {
int number1; int number2; cout << "Enter two integers to compare: "; cin >> number1 >> number2; if ( number1 == number2 ) cout << number1 << " == " << number2 << endl; if ( number1 != number2 ) cout << number1 << " != " << number2 << endl; if ( number1 < number2 ) cout << number1 << " < " << number2 << endl; if ( number1 > number2 ) cout << number1 << " > " << number2 << endl; if ( number1 <= number2 ) cout << number1 << " <= " << number2 << endl; if ( number1 >= number2 ) cout << number1 << " >= " << number2 << endl; return 0;
}</source>
Enter two integers to compare: 4 3 4 != 3 4 > 3 4 >= 3
constant integer value
<source lang="cpp">#include <iostream>
- include <iomanip>
- include <cmath>
using namespace std; int main() {
const double RATE_MIN = 5; const double RATE_MAX = 10; const double RATE_INCR = 0.5; const int YEAR_MIN = 5; const int YEAR_MAX = 30; const int YEAR_INCR = 5; /* print table header */ int year; cout << " Rate "; for (year = YEAR_MIN; year <= YEAR_MAX; year = year + YEAR_INCR) { cout << setw(2) << year << " years "; } cout << "\n"; cout << fixed << setprecision(2); double initial_balance = 10000; double rate; for (rate = RATE_MIN; rate <= RATE_MAX; rate = rate + RATE_INCR) { /* print table row */ cout << setw(5) << rate; for (int year = YEAR_MIN; year <= YEAR_MAX; year = year + YEAR_INCR) { double balance = initial_balance * pow(1 + rate / 100, year); cout << setw(10) << balance; } cout << "\n"; } return 0;
}</source>
Convert gallons to liters
<source lang="cpp">#include <iostream> using namespace std; int main() {
int gallons, liters; cout << "Enter number of gallons: "; cin >> gallons; // this inputs from the user liters = gallons * 4; // convert to liters cout << "Liters: " << liters; return 0;
}</source>
Enter number of gallons: 12 Liters: 48
Define and assign int variables
<source lang="cpp">#include <iostream>
int main() { int a=0, b=0, x=0, y=35; std::cout << "a: " << a << " b: " << b; std::cout << " x: " << x << " y: " << y << std::endl; a = 9; b = 7; y = x = a+b; std::cout << "a: " << a << " b: " << b; std::cout << " x: " << x << " y: " << y << std::endl; return 0; }</source>
a: 0 b: 0 x: 0 y: 35 a: 9 b: 7 x: 16 y: 16
Define an int variable
<source lang="cpp">#include <iostream> using namespace std;
int main() {
int length; // this declares a variable length = 7; // this assigns 7 to length cout << "The length is "; cout << length; // This displays 7 return 0;
}</source>
The length is 7"
Do bit operation on integers: AND, OR, XOR
<source lang="cpp">#include <iostream> using namespace std; int main() {
int num1, num2,iand,ior,ixor; num1 = 1; num2 = 2; iand = num1 & num2; ior = num1 | num2; ixor = num1 ^ num2; cout << num1 << " AND " << num2 << " is " << iand << endl; cout << num1 << " OR " << num2 << " is " << ior << endl; cout << num1 << " XOR " << num2 << " is " << ixor << endl; return 0;
}</source>
1 AND 2 is 0 1 OR 2 is 3 1 XOR 2 is 3
Do calculation in cout
<source lang="cpp">#include <iostream> using namespace std;
int main() {
int length; int width; length = 7; width = 5; cout << "The area is "; cout << length * width; return 0;
}</source>
The area is 35"
lists cubes from 1 to 10: int type variable calculation
<source lang="cpp">#include <iostream>
- include <iomanip>
using namespace std;
int main(){
int numb; for(numb=1; numb<=10; numb++){ cout << setw(4) << numb; //display 1st column int cube = numb*numb*numb; //calculate cube cout << setw(6) << cube << endl; //display 2nd column } return 0;
}</source>
simple FOR loop controlled by int type variable
<source lang="cpp">#include <iostream> using namespace std;
int main(){
int j; for(j=0; j<15; j++) cout << j * j << " "; cout << endl; return 0;
}</source>
Use arithmetic operator to get the product of two integers
<source lang="cpp">#include <iostream> using namespace std;
int main() {
int length; int width; int area; length = 7; width = 5; area = length * width; // compute area cout << "The area is "; cout << area; return 0;
}</source>
The area is 35"