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 ]
  

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));

If you're using Java 1.4, you can instead do:

System.out.println(Arrays.asList(array));

(This works in 1.5+ too, of course.)

for(int n: someArray) {
    System.out.println(n+" ");
}

There Are Following way to print Array

 // 1) toString()  
    int[] arrayInt = new int[] {10, 20, 30, 40, 50};  
    System.out.println(Arrays.toString(arrayInt));

// 2 for loop()
    for (int number : arrayInt) {
        System.out.println(number);
    }

// 3 for each()
    for(int x: arrayInt){
         System.out.println(x);
     }

• It is very simple way to print array without using any loop in JAVA.

  -> For, Single or simple array:

   int[] array = new int[]{1, 2, 3, 4, 5, 6};
   System.out.println(Arrays.toString(array));
  

  The Output :

        [1, 2, 3, 4, 5, 6]
  

  -> So, this 2D array can't be printed with Arrays.toString()

   int[][] array = new int[][]{{1, 2, 3, 4, 5, 6, 7}, {8, 9, 10, 11, 12,13,14}};
   System.out.println(Arrays.deepToString(array));
  

  The Output:

     [[1, 2, 3, 4, 5, 6, 7], [8, 9, 10, 11, 12, 13, 14]]
  

☻♥ Done Keep Code

Here a possible printing function:

  public static void printArray (int [] array){
        System.out.print("{ ");
        for (int i = 0; i < array.length; i++){
            System.out.print("[" + array[i] + "] ");
        }
        System.out.print("}");
    }

For example, if main is like this

public static void main (String [] args){
    int [] array = {1, 2, 3, 4};
    printArray(array);
}

the output will be { [1] [2] [3] [4] }

This is marked as a duplicate for printing a byte[]. Note: for a byte array there are additional methods which may be appropriate.

You can print it as a String if it contains ISO-8859-1 chars.

String s = new String(bytes, StandardChars.ISO_8559);
System.out.println(s);
// to reverse
byte[] bytes2 = s.getBytes(StandardChars.ISO_8559);

or if it contains a UTF-8 string

String s = new String(bytes, StandardChars.UTF_8);
System.out.println(s);
// to reverse
byte[] bytes2 = s.getBytes(StandardChars.UTF_8);

or if you want print it as hexadecimal.

String s = DatatypeConverter.printHexBinary(bytes);
System.out.println(s);
// to reverse
byte[] bytes2 = DatatypeConverter.parseHexBinary(s);

or if you want print it as base64.

String s = DatatypeConverter.printBase64Binary(bytes);
System.out.println(s);
// to reverse
byte[] bytes2 = DatatypeConverter.parseBase64Binary(s);

or if you want to print an array of signed byte values

String s = Arrays.toString(bytes);
System.out.println(s);
// to reverse
String[] split = s.substring(1, s.length() - 1).split(", ");
byte[] bytes2 = new byte[split.length];
for (int i = 0; i < bytes2.length; i++)
    bytes2[i] = Byte.parseByte(split[i]);

or if you want to print an array of unsigned byte values

String s = Arrays.toString(
               IntStream.range(0, bytes.length).map(i -> bytes[i] & 0xFF).toArray());
System.out.println(s);
// to reverse
String[] split = s.substring(1, s.length() - 1).split(", ");
byte[] bytes2 = new byte[split.length];
for (int i = 0; i < bytes2.length; i++)
    bytes2[i] = (byte) Integer.parseInt(split[i]); // might need a range check.

if you are running jdk 8.

public static void print(int[] array) {
    StringJoiner joiner = new StringJoiner(",", "[", "]");
    Arrays.stream(array).forEach(element -> joiner.add(element + ""));
    System.out.println(joiner.toString());
}


int[] array = new int[]{7, 3, 5, 1, 3};
print(array);

output:

[7,3,5,1,3]

If you are using Java 11

import java.util.Arrays;
public class HelloWorld{

     public static void main(String []args){
        String[] array = { "John", "Mahta", "Sara" };
       System.out.println(Arrays.toString(array).replace(",", "").replace("[", "").replace("]", ""));
     }
}

Output :

John Mahta Sara

In java 8 :

Arrays.stream(myArray).forEach(System.out::println);

If using Commons.Lang library, we could do:

ArrayUtils.toString(array)

int[] intArray = new int[] {1, 2, 3, 4, 5};
String[] strArray = new String[] {"John", "Mary", "Bob"};
ArrayUtils.toString(intArray);
ArrayUtils.toString(strArray);

Output:

{1,2,3,4,5}
{John,Mary,Bob}

In JDK1.8 you can use aggregate operations and a lambda expression:

String[] strArray = new String[] {"John", "Mary", "Bob"};

// #1
Arrays.asList(strArray).stream().forEach(s -> System.out.println(s));

// #2
Stream.of(strArray).forEach(System.out::println);

 // #3
 Arrays.stream(strArray).forEach(System.out::println);

/* output:
John
Mary
Bob
*/

Also, starting with Java 8, one could also take advantage of the join() method provided by the String class to print out array elements, without the brackets, and separated by a delimiter of choice (which is the space character for the example shown below)

string[] greeting = {"Hey", "there", "amigo!"};
String delimiter = " ";
String.join(delimiter, greeting) 

` The output will be "Hey there amigo!"

By using the java.util.Arrays:

String mRole = "M_XXX_ABC";        
System.out.println(Arrays.asList(mRole.split("_")).toString());

output: [M, XXX, ABC]

Use the Arrays class. It has multiple utility methods and its toString() is overriden to display array elements in a human readable way. Arrays.toString(arr)

There are several ways to print an array elements.First of all, I'll explain that, what is an array?..Array is a simple data structure for storing data..When you define an array , Allocate set of ancillary memory blocks in RAM.Those memory blocks are taken one unit ..

Ok, I'll create an array like this,

class demo{
      public static void main(String a[]){

           int[] number={1,2,3,4,5};

           System.out.print(number);
      }
}

Now look at the output,

You can see an unknown string printed..As I mentioned before, the memory address whose array(number array) declared is printed.If you want to display elements in the array, you can use "for loop " , like this..

class demo{
      public static void main(String a[]){

           int[] number={1,2,3,4,5};

           int i;

           for(i=0;i<number.length;i++){
                 System.out.print(number[i]+"  ");
           }
      }
}

Now look at the output,

Ok,Successfully printed elements of one dimension array..Now I am going to consider two dimension array..I'll declare two dimension array as "number2" and print the elements using "Arrays.deepToString()" keyword.Before using that You will have to import 'java.util.Arrays' library.

 import java.util.Arrays;

 class demo{
      public static void main(String a[]){

           int[][] number2={{1,2},{3,4},{5,6}};`

           System.out.print(Arrays.deepToString(number2));
      }
}

consider the output,

At the same time , Using two for loops ,2D elements can be printed..Thank you !

toString is a way to convert an array to string.

Also, you can use:

for (int i = 0; i < myArray.length; i++){
System.out.println(myArray[i] + " ");
}

This for loop will enable you to print each value of your array in order.