Executing lines of code only once when a condition changes in a loop

Question

In the following code :

boolean condition=false;

do{
    condition=expression;

    if(condition)
    {
        // subprogram 2
    }

    // subprogram 1

}while(condition1);

I want to execute subprogram 2 only once (when "condition" changes from false to true, it will remain true afterwards) while the do-while loop keeps advancing.

Is there a way to do it ?

Answer 1

bool ifStatementRan = false; 
do{
    condition=expression;

    if(condition && !ifStatementRan )
    {
        ifStatementRan = true;
        // subprogram 2
    }

    // subprogram 1

}while(condition1);

You will probably want to use a more descriptive variable name than "ifStatementRan" to describe what the if statement is doing.

Answer 2

You can use a done flag for subprogram 2.

boolean condition=false;
boolean subProgram2Done = false;

do{
    condition=expression;

    if(condition && subProgram2Done  == false )
    {
    // subprogram 2
    subProgram2Done  = true;
    }

    // subprogram 1

}while(condition);

Answer 3

boolean JustFirstTime=true;
int x = 0;

while(x < 10){


if(JustFirstTime)
{
    // subprogram 2
    JustFirstTime= false;
}

// subprogram 1
x++;

};