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A block of code in if statement
#include <iostream>
using namespace std;
int main() {
double result, n, d;
cout << "Enter value: ";
cin >> n;
cout << "Enter divisor: ";
cin >> d;
if(d != 0) {
cout << "d does not equal zero so division is OK" << "\n";
result = n / d;
cout << n << " / " << d << " is " << result;
}
return 0;
}Enter value: 12
Enter divisor: 21
d does not equal zero so division is OK
12 / 21 is 0.571429"
A nested if tatement
#include <iostream>
int main()
{
int firstNumber =2;
int secondNumber = 3;
if (firstNumber >= secondNumber)
{
if ( (firstNumber secondNumber) == 0) // evenly divisible?
{
if (firstNumber == secondNumber)
std::cout << "They are the same!\n";
else
std::cout << "They are evenly divisible!\n";
}
else
std::cout << "They are not evenly divisible!\n";
}
else
std::cout << "Hey! The second one is larger!\n";
return 0;
}Hey! The second one is larger!
An if-else-if ladder.
#include <iostream>
using namespace std;
int main()
{
int x;
for(x=0; x<6; x++) {
if(x==1) cout << "x is one\n";
else if(x==2) cout << "x is two\n";
else if(x==3) cout << "x is three\n";
else if(x==4) cout << "x is four\n";
else cout << "x is not between 1 and 4\n";
}
return 0;
}x is not between 1 and 4
x is one
x is two
x is three
x is four
x is not between 1 and 4
If else statement with block code
#include <iostream>
#include <cstdlib>
using namespace std;
int main()
{
int magic; // magic number
int guess; // user"s guess
magic = rand(); // get a random number
cout << "Enter your guess: ";
cin >> guess;
if (guess == magic) {
cout << "Right\n";
cout << magic << " is the magic number.\n";
}
else {
cout << "...Sorry, you"re wrong.";
if(guess > magic)
cout <<" Your guess is too high.\n";
else
cout << " Your guess is too low.\n";
}
return 0;
}Enter your guess: 3
...Sorry, you"re wrong. Your guess is too low.
If statement with else
#include <iostream>
#include <cstdlib>
using namespace std;
int main()
{
int magic; // magic number
int guess; // user"s guess
magic = rand(); // get a random number
cout << "Enter your guess: ";
cin >> guess;
if(guess == magic)
cout << "Right";
else
cout << "...Sorry, you"re wrong.";
return 0;
}Enter your guess: 3
...Sorry, you"re wrong."
if statement with variable logic operators
#include <iostream>
using namespace std;
int main() {
int a, b, c;
a = 2;
b = 3;
if(a < b)
cout << "a is less than b\n";
if(a == b)
cout << "you won"t see this\n";
cout << "\n";
c = a - b;
cout << "c contains -1\n";
if(c >= 0)
cout << "c is non-negative\n";
if(c < 0)
cout << "c is negative\n";
cout << "\n";
c = b - a; // c now contains 1
cout << "c contains 1\n";
if(c >= 0)
cout << "c is non-negative\n";
if(c < 0)
cout << "c is negative\n";
return 0;
}a is less than b
c contains -1
c is negative
c contains 1
c is non-negative
if with else
#include <iostream>
int main()
{
int firstNumber, secondNumber;
std::cout << "Please enter a big number: ";
std::cin >> firstNumber;
std::cout << "\nPlease enter a smaller number: ";
std::cin >> secondNumber;
if (firstNumber > secondNumber)
std::cout << "\nThanks!\n";
else
std::cout << "\nOops. The second is bigger!";
return 0;
}Please enter a big number: 123
Please enter a smaller number: 12
Thanks!
Proper use of braces with an if statement
#include <iostream>
int main()
{
int x = 12;
if (x > 10)
{
if (x > 100)
std::cout << "More than 100, Thanks!\n";
}
else // now works as intended!
std::cout << "Less than 10, Thanks!\n";
return 0;
}Use an int value to control the if
#include <iostream>
using namespace std;
int main()
{
int a, b;
cout << "Enter numerator: ";
cin >> a;
cout << "Enter denominator: ";
cin >> b;
if(b)
cout << "Result: " << a / b << "\n";
else
cout << "Cannot divide by zero.\n";
return 0;
}Enter numerator: 2
Enter denominator: 4
Result: 0
