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(intArray); // prints something like '[I@3343c8b3'
But usually, we'd actually want something more like [1, 2, 3, 4, 5]
. What's the simplest way of doing that? Here are some example inputs and outputs:
// Array of primitives: int[] intArray = new int[] {1, 2, 3, 4, 5}; //output: [1, 2, 3, 4, 5] // Array of object references: String[] strArray = new String[] {"John", "Mary", "Bob"}; //output: [John, Mary, Bob]
Arrays in java are used to hold similar data types values.
Let us first declare and initialize an unsorted Short array. short[] arr = new short[] { 35, 25, 18, 45, 77, 21, 3 }; Now, let us short the 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:
String[] array = new String[] {"John", "Mary", "Bob"}; System.out.println(Arrays.toString(array));
Output:
[John, Mary, Bob]
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 ]
Always check the standard libraries first.
import java.util.Arrays;
Then try:
System.out.println(Arrays.toString(array));
or if your array contains other arrays as elements:
System.out.println(Arrays.deepToString(array));
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