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for loop

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Executes a loop.

Used as a shorter equivalent of a while loop.

Contents

Syntax

for ( Template:sparam ; Template:sparam ; Template:sparam ) Template:sparam

Explanation

The above syntax produces code equivalent to:

{
Template:sparam ;
while ( Template:sparam ) {
Template:sparam
Template:sparam ;
}

}

The Template:sparam is executed before the execution of the loop. The Template:sparam shall evaluate to value, convertible to bool. It is evaluated before each iteration of the loop. The loop continues only if its value is true. The Template:sparam is executed on each iteration, after which Template:sparam is executed.

If the execution of the loop needs to be terminated at some point, break statement can be used as terminating statement.

If the execution of the loop needs to be continued at the end of the loop body, continue statement can be used as shortcut.

Keywords

for

Example

#include <iostream>
#include <vector>
 
int main() 
{
    for (int i = 0; i < 10; i++) {
        std::cout << i << " ";
    }
 
    std::cout << '\n';
 
    for (int j = 2; j < 9; j = j + 2) {
        std::cout << j << " ";
    }
 
    std::cout << '\n';
 
    // Check also the new Range-based for loop (C++11)
    // for iterating with containers.
    std::vector<int> v = {3, 1, 4, 1, 5, 9};
    for (std::vector<int>::iterator iter = v.begin();
         iter != v.end();
         ++iter) {
        std::cout << *iter << " ";
    }
 
    std::cout << '\n';
}

Output:

0 1 2 3 4 5 6 7 8 9
2 4 6 8
3 1 4 1 5 9

See Also