Question

I am having som slight difficulties with the following problem.

I have initialized a boolean array called numberArray with 31 indexes. The user is supposed to enter 5 digits between 1 and 30, and each time a digit is entered, the program is supposed to set the proper index to true. For instance, if I enter 5 then:

numberArray[5] = true;

However, if the user enters the value 5 a second time, a message should be given to the user that this number has already been entered, and so the user has to choose a different value. I have tried to create a loop as follows:

public void enterArrayValues() {
    for(int i = 1; i < 6; i++) {
        System.out.print("Give " + i + ". number: ");
        int enteredNumber = input.nextInt();
        while (numberArray[enteredNumber] = true) {
            System.out.println("This number has already been chosen.");
            System.out.print("Give " + i + ". number again: ");
            enteredNumber = input.nextInt();
        }
        numberArray[enteredNumber] = true;
    }
}

The problem is that when I run the program, I automatically get the message “The number has already been chosen” no matter what I enter. Even the first time I enter a number. I don’t get this. Isn’t all the values in the boolean array false by default?

I would greatly appreciate it if someone could help me with this!

Answer 1

while (numberArray[enteredNumber] = true) {

make that

while (numberArray[enteredNumber] == true) {

or change to

while (true == numberArray[enteredNumber]) {

or simply drop the ==true

while (numberArray[enteredNumber]) {