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Java Java Objects (Retired) Creating the MVP Prompting for Guesses

Posted by Youngchul Kim
Youngchul Kim
4,258 Points

Can you pass a returned value as a parameter for another method as long as it has the correct type?

In following scenario, why passing a value named "guess" from promptForGuess() works with applyGuess(Char letter)? when the latter one is specifically asking a parameter Char named "letter"? Is that just a placeholder?

Can I use applyGuess with any names so long as the passing value is workable with Char?

//from Prompter.java
  public boolean promptForGuess() {
    Console console = System.console();
    String guessAsString = console.readLine("Enter a letter:  ");
    char guess = guessAsString.charAt(0);
    return mGame.applyGuess(guess);

//from Game.java
  public boolean applyGuess(Char letter) {
    boolean isHit = mAnswer.indexOf(letter) >= 0;
    if (isHit) {
      mHits += letter;
    } else {
      mMisses += letter;
    }
    return isHit; 
  }

2 Answers

Cian Mac Mahon
Cian Mac Mahon
17,657 Points

You are exactly right. The name that you give when defining the parameter is simply a placeholder for you to use when creating the function. You can pass a variable with any name into the function, so long as it conforms to the type.

Youngchul Kim
Youngchul Kim
4,258 Points

Thanks for the quick clarification!

Rob Bridges
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Rob Bridges
Full Stack JavaScript Techdegree Graduate 35,467 Points
Rob Bridges
.a{fill-rule:evenodd;}techdegree seal-36
Rob Bridges
Full Stack JavaScript Techdegree Graduate 35,467 Points

Hey there YoungChul.

You are correct, applyGuess takes a character as parameter, as long as you pass it in a character to check, it will do it's task, you'd of course run into trouble if you tried to pass it an int or a boolean, but what's above is perfectly acceptable Java.