返回的布尔值如何在参数中工作（Java）

Question

so the below code:

  private void pickNext()
  {

        last = next;
        next = (int)(Math.random() * 9 + 1);
        System.out.print(""+last + next);
        while(last == next)
        {
        next = (int)(Math.random() * 9 + 1);
        }

  }
  public boolean guessHigh()
  {
     pickNext();
     return next > last;
  }
  public boolean guessLow()
  {
     pickNext();
     return next < last;
  }

basically says that two integers (already instantiated and next is defined already) next and last are changed so that last is next, then next is randomly generated so that it is not the previous number. Then guesslow and guesshigh returns if next>last or nextMy question is what does it return? does it return true or false? or like a number? In another part of my code:

public void update(boolean arg) //arg is true means player guessed correct {

        if()
        {
           //random other code
        }
        else
        {
          //other code
        }

how would I write the if statement so that if it is the guessLow or guessHigh are true it does this, and if not it does this? Help is greatly appreciated

Answer 1

The two methods return a boolean. In the if statement you just write the name of the methods as:

if ( guessHigh() ) {..}
else {..}

Or if you get it as a parameter:

public void update(boolean arg){
    if ( arg ) {..}
    else {..}
}

In that case I'd suggest to call the parameter with more meaningful name as eg hasCorrectlyGuessed. So you can write the if statement as

public void update(boolean hasCorrectlyGuessed){
        if ( hasCorrectlyGuessed ) {..}
        else {..}
    }

See official tutorial from Oracle about if-then-else.

Answer 2

Based on the definition of the arg parameter; true if player guessed correctly. And arg will be true or false ,

if (arg) {
    // player guessed correctly.
} else {
    // player guessed incorrectly.
}

which is the same as

if (arg == true) {
    // player guessed correctly.
} else {
    // player guessed incorrectly.
}

You could also reverse the logic like

if (!arg) {
    // player guessed incorrectly.
} else {
    // player guessed correctly.
}

or

if (arg == false) {
    // player guessed incorrectly.
} else {
    // player guessed correctly.
}