<Tr> <Td> Control flow </Td> </Tr> <P> In most computer programming languages, a do while loop is a control flow statement that executes a block of code at least once, and then repeatedly executes the block, or not, depending on a given boolean condition at the end of the block . </P> <P> The do while construct consists of a process symbol and a condition . First, the code within the block is executed, and then the condition is evaluated . If the condition is true the code within the block is executed again . This repeats until the condition becomes false . Because do while loops check the condition after the block is executed, the control structure is often also known as a post-test loop . Contrast with the while loop, which tests the condition before the code within the block is executed, the do - while loop is an exit - condition loop . This means that the code must always be executed first and then the expression or test condition is evaluated . If it is true, the code executes the body of the loop again . This process is repeated as long as the expression evaluates to true . If the expression is false, the loop terminates and control transfers to the statement following the do - while loop . In other words, whereas a while loop sets the truth of a statement as a condition precedent for the code's execution, a do - while loop provides for the action's ongoing execution subject to defeasance by the condition's falsity, which falsity (i.e., the truth of the condition's negation) is set as a condition subsequent . </P> <P> It is possible, and in some cases desirable, for the condition to always evaluate to true, creating an infinite loop . When such a loop is created intentionally, there is usually another control structure (such as a break statement) that allows termination of the loop . </P>

The loop which execute once before condition is checked