#includeint main() { // Declare two integer variables int theInt, theIntSquared; // Prompt for input and retrieve an integer cout << "Enter an integer: "; cin >> theInt; // Perform calculation theIntSquared = theInt * theInt; // Display the result cout << theInt << " squared is " << theIntSquared << endl; // These next few lines may not be necessary // for some compilers/environments // Declare a character variable char wait; // Wait for user to input a character cin >> wait; // Indicate success status to OS return 0; }
int myAge;
int theInt, theIntSquared;
int theInt = 5, theIntSquared = theInt * theInt;
- bool
- constants: true, false
- char
- constants: 'j', '2', '\n', '\t', '\\', '\0', '\''
- int
- constants: 52, -3, 072, 0xF1F1
- double
- constants: 3.1415, -4.0, 8.27E18, 1.5e-5
- string constants
- "Hello, world!\n", "\"Hello, world\" I said.", ""
const double Pi = 3.141592; const int MAX_GUESSES = 10;
theIntSquared = theInt * theInt; x = y = z = 0; x = 5 + (z = 2);
+ - * / %
Examples:
7 / 2 -> 2
7.0 / 2 -> 3.5
double(7) / 2
6.0 / 2 -> 3.0
1/2 -> ?
54 % 7 -> 5
int x, y = 6;
double z = 5.2;
x = y * z;
int * double -> double, int = double -> ?
Highest to lowest:
()Left to right: * / % + -
* / %
+ -
=
Right to left: =
Undefined: ()
Examples:
8 + 6 * 4 / 2 - 1 = (8 + ((6 * 4) / 2)) - 1
x = y = z = 0 -> x = (y = (z = 0))
+= -= *= /= %= ++ --
theInt = theInt + 5 ==> theInt += 5
theInt = theInt + 1 ==> theInt += 1 ==> theInt++
theInt++ vs. ++theInt
Same precedence as =: += -= *= /= %=
Higher precedence than */%: ++, --
int main() { int m, n = 2; // This expression does nothing (has no "side-effects") 1 * 2 + 3 / 4 - 5 - 6 + 7 - 8; // This one is equivalent to n = n + 6 n += 6; cout << "n = " << n << endl; // This one is equivalent to n = n / (2 + 1) n /= 2 + 1; cout << "n = " << n << endl; // This is equivalent to n = n + 1, or n += 1 n++; cout << "n = " << n << endl; // What's the result here? m = n++; cout << "m = " << m << ", n = " << n << endl; // How about here? m = ++n; cout << "m = " << m << ", n = " << n << endl; // This expression has unpredictable side-effects. n = (n = 10) * 4 + (n = n * 10) * 2; cout << "n = " << n << endl; return 0; }Output:
n = 8 n = 2 n = 3 m = 3, n = 4 m = 5, n = 5 n = 240
Input stream (istream) cin
Output stream (ostream) cout
cin >>cin >> anIntVar >> aDoubleVar >> aCharVar;
cout <<cout << anIntVar + 2 << aDoubleVar / 3 << aCharVar;
Double value output formatting (consider this a formula)cout.setf(ios::fixed)
cout.setf(ios::showpoint)
cout.precision(2);
Input a length given in whole centimeters. Convert to inches (cm / 2.54) and output the number of whole feet and remaining inches. You may convert double to int using a typecast, even though the effect of doing so is compiler dependent (most compilers truncate). Display inches to 2 decimal places.
Ex. 100 cms = 3 ft. 3.37 in.