The Wayback Machine - https://web.archive.org/web/20141224012223/http://en.cppreference.com/w/cpp/language/do
Namespaces
Variants
Views
Actions

do-while loop

From cppreference.com
< cpp‎ | language
 
C++
 
C++ language
 
Statements
Labels
label : statement
Expression statements
expression ;
Compound statements
{ statement... }
Selection statements
if
switch
Iteration statements
while
do-while
for
range for(C++11)
Jump statements
break
continue
return
goto
Declaration statements
declaration ;
Try blocks
try compound-statement handler-sequence
 

Executes a statement repeatedly, until the value of condition becomes false. The test takes place after each iteration.

Contents

[edit] Syntax

attr(optional) do statement while ( expression ) ;
attr(C++11) - any number of attributes
expression - any expression which is contextually convertible to bool. This expression is evaluated after each iteration, and if it yields false, the loop is exited.
statement - any statement, typically a compound statement, which is the body of the loop


[edit] Notes

statement is always executed at least once, even if expression always yields false. If it should not execute in this case, while or for loop may be used.

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.

[edit] Keywords

do, while

[edit] Example

Run this code
#include <iostream>
 
int main()
{
    int i = 0;
    do i++;
    while (i < 10);
 
    std::cout << i << '\n';
 
    i = 11;
    do i = i + 10;
    while (i < 10); // the condition is false before the loop
 
    std::cout << i << '\n';
 
    int j = 2;
    do {
        j += 2;
        std::cout << j << " ";
    } while (j < 9);
}

Output: 

10
21
4 6 8 10
Retrieved from "http://en.cppreference.com/mwiki/index.php?title=cpp/language/do&oldid=49905"