check if all number from 1-9 are in 3x3 array

Question

the method checks if all the numbers from 1-9 are in a given 3x3 array. i keep getting true even when the array doesnt contain all the numbers and has one of the numers twice. where is my error?

public boolean allThere(){
    int counter=0;
    boolean t;
    for(int k=1; k<10;k++) {
        t=true;

        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                if(arr[i][j]==k){
                    counter++;
                    t=false;

                }
                if(t=false) break;
            }
            if(t=false) break;
        }


    }
    if(counter==9) return true;
    else return false;
}

Answer 1

The problem is an operator = assigns the value to variable t Whereas == is an equality operator that checks the variable value. Change it to

if (t == false) break;

You can also use ! not operator

if (!t) break;

You can also see this algorithm implemented in java

public boolean allThere(int[][] arr) {

    int[] numbers = new int[]{1, 1, 1, 1, 1, 1, 1, 1, 1};

    for (int i = 0; i < 3; i++) {
        for (int j = 0; j < 3; j++) {
            int value = arr[i][j];
            numbers[value-1]--;
        }
    }

    for (int bool: numbers) {
        if (bool != 0) {
            return false;
        }
    }

    return true;
    
}