for (int i = 0, j = 2; i < 3; i++, j--){
std::cout << "i=" << i << ",";
std::cout << "j=" << j << ";";
}
// Outputs: i=0,j=2;i=1,j=1;i=2,j=0;
C++ Loops
Several variations
Break statements
int password, times = 0;
while (password != 1234) {
if (times++ >= 3) {
std::cout << "Locked!\n";
break;
}
std::cout << "Password: ";
std::cin >> password; // input
}
Range-based (Since C++11)
for (int n : {1, 2, 3, 4, 5}) {
std::cout << n << " ";
}
// Outputs: 1 2 3 4 5
std::string hello = "QuickRef.ME";
for (char c: hello)
{
std::cout << c << " ";
}
// Outputs: Q u i c k R e f . M E
for_each (Since C++11)
#include <iostream>
int main()
{
auto print = [](int num) { std::cout << num << std::endl; };
std::array<int, 4> arr = {1, 2, 3, 4};
std::for_each(arr.begin(), arr.end(), print);
return 0;
}
Infinite loop
while (true) { // true or 1
std::cout << "infinite loop";
}
for (;;) {
std::cout << "infinite loop";
}
for(int i = 1; i > 0; i++) {
std::cout << "infinite loop";
}
Continue statements
for (int i = 0; i < 10; i++) {
if (i % 2 == 0) {
continue;
}
std::cout << i;
} // Outputs: 13579
Do-while
int i = 1;
do {
std::cout << i++;
} while (i <= 5);
// Outputs: 12345
While
int i = 0;
while (i < 6) {
std::cout << i++;
}
// Outputs: 012345
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