change do-while loop to while

[Souverain]

Hi i know its probably an easy one but i just cant figure that one out i might be tired ... i need to change the Do-while loop for while.

import java.util.*;
public class DoWhile2
{
   public static void main (String[] args)
   {
      final int AGE_MIN = 0,
      AGE_MAX = 125;
      int age ;
      boolean valide ;
      String tmp;
      Scanner clavier = new Scanner(System.in);
      // saisir et valider l'âge entre 2 bornes
      do {
         System.out.println("Tapez l'âge d'une personne entre "+ AGE_MIN +
               " et " + AGE_MAX + ": ");
         age = clavier.nextInt();
         valide = (age >= AGE_MIN && age <= AGE_MAX);
         if (!valide)
            System.out.println(age + " est hors bornes");
      } while (!valide);
      System.out.println("Age saisi : " + age + " an(s)");
      char genre ;
      // saisir et valider le genre (parmi f, F, m et M)
      do {
         System.out.println("Tapez f, F, m ou M pour le genre : ");
         tmp = clavier.next();
         genre = tmp.charAt(0);
         valide = (genre == 'f' || genre == 'F' || genre == 'm' || genre == 'M';
         if (! valide)
            System.out.println("Le caractère saisi " + genre + " est invalide");
      } while (!valide);
      System.out.println("Caractère saisi pour le genre : " + genre );
   }
}

never-mind the french ...

[pbrockway2]

Hi Souverain, welcome to the forums!

When you post code, use the "code" tags. In the pane where you compose your post it's a little # sign next to the speech bubble you used to "quote" the code. Or you can enter the tags by hand: put [code] at the start of the code, and [/code] at the end.

The following are equivalent (I think):

boolean cond;
do {
    // some code
    cond = some_condition;
    // more code
} while(!cond);

boolean cond = false;
while(cond {
    // some code
    cond = some_condition;
    // more code
}

Personally I prefer a while loop (unless it's really contrived to have one) since it states the "governing" condition right at the start.

[Souverain]

Thank you ! will do for the code

[Nouish]

Hi Souverain, welcome to the forums!

When you post code, use the "code" tags. In the pane where you compose your post it's a little # sign next to the speech bubble you used to "quote" the code. Or you can enter the tags by hand: put [code] at the start of the code, and [/code] at the end.

The following are equivalent (I think):

boolean cond;
do {
    // some code
    cond = some_condition;
    // more code
} while(!cond);

boolean cond = false;
while(cond {
    // some code
    cond = some_condition;
    // more code
}

Personally I prefer a while loop (unless it's really contrived to have one) since it states the "governing" condition right at the start.

No, a do-while loop will execute one time before checking the condition.

do {
	System.out.println("This line will be printed once, before the condition is checked.");
} while (false);

Your while code example would not even execute once, because the condition is always false.

[pbrockway2]

Opps! Yes, you're right: the while loop should have said "while(!cond){". Thanks for the correction.

Using the OP's variable names it would look like:

boolean valide = false;
while(!valide {
    // some code
    valide = some_condition;
    // more code
}