how to compare two string arrays without java utils

Question

Check to see if the array arr1 contain the same elements as arr2 in the same order in java.

for example:

    isTheSame({"1", "2", "3"}, {"1", "2", "3"}) → true
    isTheSame({"1", "2", "3"}, {"2", "1", "1"}) → false
    isTheSame({"1", "2", "3"}, {"3", "1", "2"}) → false

so far i have

public boolean isTheSame(String[] arr1, String[] arr2)
{
   if (arr1.length == arr2.length)
   {
      for (int i = 0; i < arr1.length; i++)
       {
          if (arr1[i] == arr2[i])
          {
            return true;
          }
       }
    }
    return false;  
 }

The problem with this is that it only compares the first element of the two arrays.

Answer 1

You are iterating until you find a match. You should instead be looking for a String which doesn't match and you should be using equals not ==

// same as Arrays.equals()
public boolean isTheSame(String[] arr1, String[] arr2) {
    if (arr1.length != arr2.length) return false;
    for (int i = 0; i < arr1.length; i++)
        if (!arr1[i].equals(arr2[i]))
            return false;
    return true;
}

FYI This is what Arrays.equals does as it handle null values as well.

public static boolean equals(Object[] a, Object[] a2) {
    if (a==a2)
        return true;
    if (a==null || a2==null)
        return false;

    int length = a.length;
    if (a2.length != length)
        return false;

    for (int i=0; i<length; i++) {
        Object o1 = a[i];
        Object o2 = a2[i];
        if (!(o1==null ? o2==null : o1.equals(o2)))
            return false;
    }

    return true;
}