equals vs Arrays.equals in Java

java arrays equality
PandaConda picture PandaConda · Jan 8, 2012 · Viewed 175.8k times · Source

When comparing arrays in Java, are there any differences between the following 2 statements?

Object[] array1, array2;
array1.equals(array2);
Arrays.equals(array1, array2);

And if so, what are they?

Answer

Peter Lawrey picture Peter Lawrey · Jan 8, 2012

array1.equals(array2) is the same as array1 == array2, i.e. is it the same array. As @alf points out it's not what most people expect.

Arrays.equals(array1, array2) compares the contents of the arrays.

Similarly array.toString() may not be very useful and you need to use Arrays.toString(array).

Related questions

Java: How to test on array equality?

Why is the following code printing "Different."? boolean[][] a = { {false,true}, {true,false} }; boolean[][] b = { {false,true}, {true,false} }; if (Arrays.equals(a, b) || a == b) System.out.println("Equal."); else System.out.println("Different.");

Read More
How do I declare and initialize an array in Java?

How do I declare and initialize an array in Java?

Read More
What's the simplest way to print a Java array?

In Java, arrays don't override toString(), so if you try to print one directly, you get the className + '@' + the hex of the hashCode of the array, as defined by Object.toString(): int[] intArray = new int[] {1, 2, 3, 4, 5}; System.out.println(…

Read More