What’s the simplest way to print a Java array?

Since Java 5 you can use Arrays.toString(arr) or Arrays.deepToString(arr) for arrays within arrays. Note that the Object[] version calls .toString() on each object in the array. The output is even decorated in the exact way you’re asking.

Examples:

• Simple Array: String[] array = new String[] {"John", "Mary", "Bob"}; System.out.println(Arrays.toString(array)); Output: [John, Mary, Bob]
• Nested Array: String[][] deepArray = new String[][] {{"John", "Mary"}, {"Alice", "Bob"}}; System.out.println(Arrays.toString(deepArray)); //output: [[Ljava.lang.String;@106d69c, [Ljava.lang.String;@52e922] System.out.println(Arrays.deepToString(deepArray)); Output: [[John, Mary], [Alice, Bob]]
• double Array: double[] doubleArray = { 7.0, 9.0, 5.0, 1.0, 3.0 }; System.out.println(Arrays.toString(doubleArray)); Output: [7.0, 9.0, 5.0, 1.0, 3.0 ]
• int Array: int[] intArray = { 7, 9, 5, 1, 3 }; System.out.println(Arrays.toString(intArray)); Output: [7, 9, 5, 1, 3 ]