无法使用布尔值在if语句内返回

Question

I'm trying to make a boolean method, but it's not recognizing I have a return statement. What should I do?

public boolean isThreeKind( int rankHist[]) {
  for (int i=0;i<=13;i++){
      if (rankHist[i]>=3){
          return true;
      }else{
          return false;
      }

  }
}

Answer 1

Your code does not make sense. There is no point in having a loop if you're always going to run the code inside the loop exactly once. I think you must have misunderstood. What are you trying to do?

Answer 2

Assuming the method only has to return true or false if it is greater than equal to 3 , would recommend to keep it simple.

Also, Please Note:

• Loop through the i=0 to i< rankHist.length incase the array contains less than 13 elements you will encounter an ArrayOutOfBoundException.

• If it contains more than 13 elements, the output might be incorrect.

.

public boolean isThreeKind( int rankHist[]) {

 for (int i=0;i<rankHist.length;i++){
      if (rankHist[i]>=3){ 
          return true; 
      }
  }

  return false;
}

Answer 3

This is literally what your code is doing right now:

public boolean isThreeKind( int rankHist[]) {
    return rankHist[0] >= 3;
}

That is it, and I am assuming this is not what you are attempting to do. So if you tell us what you are actually trying to accomplish we can help you more.

Answer 4

In java, You always gotta keep track of returning something EVERYWHERE the method can exit. If it can exit without hitting a return statement, you'll see that error.

So, for your code, to modify it and make it see it, you would need to have it say:

public boolean isThreeKind( int rankHist[]) {
  for (int i=0;i<=13;i++){
      if (rankHist[i]>=3){
          return true;
      }else{
          return false;
      }

  }
return false;
}

Or true, if you would rather that.

Answer 5

You should avoid multiple return statement.
You can use a flag. Declare the flag outside the for loop, then assign the value accordingly, and do not miss the break statement .
Do it like that:

public boolean isThreeKind( int rankHist[]) {
  boolean value = false;
  for (int i=0;i<=13;i++){
      if (rankHist[i]>=3){
          value = true;
          break;
      }    
  }
  return value;
}

Answer 6

I think what he wants is if every element in the 13 are >=3, he should return a true, else ways he should return a false.

public boolean isThreeKind( int rankHist[]) 
{
  for (int i=0;i<=13;i++)
  {
      if (rankHist[i]<3)
      {
          return false; // Will return false if either of the element have value <3
      }
  }
  return true;  // Will return true only if all the 13 elements have value >=3
}