From what I see you just try to see if they are equal, if this is true, just go with something like this:
boolean areEqual = Arrays.equals(arr1, arr2);
This is the standard way of doing it.
Please note that the arrays must be also sorted to be considered equal, from the JavaDoc:
Two arrays are considered equal if both arrays contain the same number of elements, and all corresponding pairs of elements in the two arrays are equal. In other words, two arrays are equal if they contain the same elements in the same order.
Sorry for missing that.
Answer from comanitza on Stack OverflowFrom what I see you just try to see if they are equal, if this is true, just go with something like this:
boolean areEqual = Arrays.equals(arr1, arr2);
This is the standard way of doing it.
Please note that the arrays must be also sorted to be considered equal, from the JavaDoc:
Two arrays are considered equal if both arrays contain the same number of elements, and all corresponding pairs of elements in the two arrays are equal. In other words, two arrays are equal if they contain the same elements in the same order.
Sorry for missing that.
use Arrays.equals(ary1,ary2); // returns boolean value
EDIT
you can use Arrays.deepEquals(ary1,ary2) to compare 2D arrays as well
also check this link for comparision comparision between Arrays.equls(ar1,ar2) and Arrays.deepEquals(ar1,ar2)
Java Arrays.equals() returns false for two dimensional arrays
EDIT 2
if you dont want to use these library methods then you can easily implement your method like this:
public static boolean ArrayCompare(int[] a, int[] a2) {
if (a==a2) // checks for same array reference
return true;
if (a==null || a2==null) // checks for null arrays
return false;
int length = a.length;
if (a2.length != length) // arrays should be of equal length
return false;
for (int i=0; i<length; i++) // compare array values
if (a[i] != a2[i])
return false;
return true;
}
First things first, you need to loop to < a.length rather than a.length - 1. As this is strictly less than you need to include the upper bound.
So, to check all pairs of elements you can do:
for (int i = 0; i < a.length; i++) {
for (int k = 0; k < a.length; k++) {
if (a[i] != a[k]) {
//do stuff
}
}
}
But this will compare, for example a[2] to a[3] and then a[3] to a[2]. Given that you are checking != this seems wasteful.
A better approach would be to compare each element i to the rest of the array:
for (int i = 0; i < a.length; i++) {
for (int k = i + 1; k < a.length; k++) {
if (a[i] != a[k]) {
//do stuff
}
}
}
So if you have the indices [1...5] the comparison would go
1 -> 21 -> 31 -> 41 -> 52 -> 32 -> 42 -> 53 -> 43 -> 54 -> 5
So you see pairs aren't repeated. Think of a circle of people all needing to shake hands with each other.
Try this or purpose will solve with lesser no of steps
for (int i = 0; i < a.length; i++)
{
for (int k = i+1; k < a.length; k++)
{
if (a[i] != a[k])
{
System.out.println(a[i]+"not the same with"+a[k]+"\n");
}
}
}
Hello, I'm currently learning java by creating a project, it's going to be a poker game.
I have a card class, each card has its suit and rank, there are 4 suits and 12 ranks.
I created 2 arrays, 1 is responsible for holding all cards of decks and the other one holds players cards (currently it's 1 v 1 game, so this array holds 4 cards only).
I put cards in first array by: deck.add(new Card(i,x), where 'i' is 0-3, and 'x' is 0-12, then I randomize order of that array by shuffle method and then put first 4 cards of first array to second array.
Right now I wanna compare 2 cards by ranks and later by suits. I have getters in cards class but I don't know how to use it for arrays.
When I create cards this way:
Card a = new Card(3,11);
Card b = new Card(2,1);
I can use a.getRank and b.getRank and compare them, but I don't know how I can use it for cards created in loop directly to array, because I can't use getRank. Could you please give me a hint? Thank you.