Vfrdtyky

Always check the standard libraries first. Try:

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

or if your array contains other arrays as elements:

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

This is nice to know, however, as for "always check the standard libraries first" I'd never have stumbled upon the trick of Arrays.toString( myarray )

--since I was concentrating on the type of myarray to see how to do this. I didn't want to have to iterate through the thing: I wanted an easy call to make it come out similar to what I see in the Eclipse debugger and myarray.toString() just wasn't doing it.

import java.util.Arrays;

.

.

.

System.out.println( Arrays.toString( myarray ) );

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

*/

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.)

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!".

Arrays.toString

As a direct answer, the solution provided by several, including @Esko, using the Arrays.toString and Arrays.deepToString methods, is simply the best.

Java 8 - Stream.collect(joining()), Stream.forEach

Below I try to list some of the other methods suggested, attempting to improve a little, with the most notable addition being the use of the Stream.collect operator, using a joining Collector, to mimic what the String.join is doing.

int ints = new int {1, 2, 3, 4, 5};

System.out.println(IntStream.of(ints).mapToObj(Integer::toString).collect(Collectors.joining(", ")));

System.out.println(IntStream.of(ints).boxed().map(Object::toString).collect(Collectors.joining(", ")));

System.out.println(Arrays.toString(ints));



String strs = new String {"John", "Mary", "Bob"};

System.out.println(Stream.of(strs).collect(Collectors.joining(", ")));

System.out.println(String.join(", ", strs));

System.out.println(Arrays.toString(strs));



DayOfWeek  days = { FRIDAY, MONDAY, TUESDAY };

System.out.println(Stream.of(days).map(Object::toString).collect(Collectors.joining(", ")));

System.out.println(Arrays.toString(days));



// These options are not the same as each item is printed on a new line:

IntStream.of(ints).forEach(System.out::println);

Stream.of(strs).forEach(System.out::println);

Stream.of(days).forEach(System.out::println);

Arrays.deepToString(arr) only prints on one line.

int table = new int[2][2];

To actually get a table to print as a two dimensional table, I had to do this:

System.out.println(Arrays.deepToString(table).replaceAll("],", "]," + System.getProperty("line.separator")));

It seems like the Arrays.deepToString(arr) method should take a separator string, but unfortunately it doesn't.

Prior to Java 8

We could have used Arrays.toString(array) to print one dimensional array and Arrays.deepToString(array) for multi-dimensional arrays.

Java 8

Now we have got the option of Stream and lambda to print the array.

Printing One dimensional Array:

public static void main(String args) {

    int intArray = new int {1, 2, 3, 4, 5};

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



    //Prior to Java 8

    System.out.println(Arrays.toString(intArray));

    System.out.println(Arrays.toString(strArray));



    // In Java 8 we have lambda expressions

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

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

}

The output is:

[1, 2, 3, 4, 5]

[John, Mary, Bob]

1

2

3

4

5

John

Mary

Bob

Printing Multi-dimensional Array
Just in case we want to print multi-dimensional array we can use Arrays.deepToString(array) as:

public static void main(String args) {

    int int2DArray = new int { {11, 12}, { 21, 22}, {31, 32, 33} };

    String str2DArray = new String{ {"John", "Bravo"} , {"Mary", "Lee"}, {"Bob", "Johnson"} };



    //Prior to Java 8

    System.out.println(Arrays.deepToString(int2DArray));

    System.out.println(Arrays.deepToString(str2DArray));



    // In Java 8 we have lambda expressions

    Arrays.stream(int2DArray).flatMapToInt(x -> Arrays.stream(x)).forEach(System.out::println);

    Arrays.stream(str2DArray).flatMap(x -> Arrays.stream(x)).forEach(System.out::println);

} 

Now the point to observe is that the method Arrays.stream(T), which in case of int returns us Stream<int> and then method flatMapToInt() maps each element of stream with the contents of a mapped stream produced by applying the provided mapping function to each element.

The output is:

[[11, 12], [21, 22], [31, 32, 33]]

[[John, Bravo], [Mary, Lee], [Bob, Johnson]]

11

12

21

22

31

32

33

John

Bravo

Mary

Lee

Bob

Johnson

for(int n: someArray) {

    System.out.println(n+" ");

}

Different Ways to Print Arrays in Java:

1. 
   

   Simple Way

   
   
   

   List<String> list = new ArrayList<String>();
   
   list.add("One");
   
   list.add("Two");
   
   list.add("Three");
   
   list.add("Four");
   
   // Print the list in console
   
   System.out.println(list);
   
   

   
   

Output:
[One, Two, Three, Four]

2. 
   

   Using toString()

   
   
   

   String array = new String { "One", "Two", "Three", "Four" };
   
   System.out.println(Arrays.toString(array));
   
   

   
   

Output: [One, Two, Three, Four]

3. 
   

   Printing Array of Arrays

   
   
   

   String arr1 = new String { "Fifth", "Sixth" };
   
   String arr2 = new String { "Seventh", "Eight" };
   
   String arrayOfArray = new String { arr1, arr2 };
   
   System.out.println(arrayOfArray);
   
   System.out.println(Arrays.toString(arrayOfArray));
   
   System.out.println(Arrays.deepToString(arrayOfArray));
   
   

   
   

Output: [[Ljava.lang.String;@1ad086a [[Ljava.lang.String;@10385c1,
[Ljava.lang.String;@42719c] [[Fifth, Sixth], [Seventh, Eighth]]

Resource: Access An Array

Using regular for loop is the simplest way of printing array in my opinion.
Here you have a sample code based on your intArray

for (int i = 0; i < intArray.length; i++) {

   System.out.print(intArray[i] + ", ");

}

It gives output as yours
1, 2, 3, 4, 5

I came across this post in Vanilla #Java recently. It's not very convenient writing Arrays.toString(arr);, then importing java.util.Arrays; all the time.

Please note, this is not a permanent fix by any means. Just a hack that can make debugging simpler.

Printing an array directly gives the internal representation and the hashCode. Now, all classes have Object as the parent-type. So, why not hack the Object.toString()? Without modification, the Object class looks like this:

public String toString() {

    return getClass().getName() + "@" + Integer.toHexString(hashCode());

}

What if this is changed to:

public String toString() {

    if (this instanceof boolean)

        return Arrays.toString((boolean) this);

    if (this instanceof byte)

        return Arrays.toString((byte) this);

    if (this instanceof short)

        return Arrays.toString((short) this);

    if (this instanceof char)

        return Arrays.toString((char) this);

    if (this instanceof int)

        return Arrays.toString((int) this);

    if (this instanceof long)

        return Arrays.toString((long) this);

    if (this instanceof float)

        return Arrays.toString((float) this);

    if (this instanceof double)

        return Arrays.toString((double) this);

    if (this instanceof Object)

        return Arrays.deepToString((Object) this);

    return getClass().getName() + "@" + Integer.toHexString(hashCode());

}

This modded class may simply be added to the class path by adding the following to the command line: -Xbootclasspath/p:target/classes.

Now, with the availability of deepToString(..) since Java 5, the toString(..) can easily be changed to deepToString(..) to add support for arrays that contain other arrays.

I found this to be a quite useful hack and it would be great if Java could simply add this. I understand potential issues with having very large arrays since the string representations could be problematic. Maybe pass something like a System.outor a PrintWriter for such eventualities.

It should always work whichever JDK version you use:

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

It will work if the Array contains Objects. If the Array contains primitive types, you can use wrapper classes instead storing the primitive directly as..

Example:

int a = new int{1,2,3,4,5};

Replace it with:

Integer a = new Integer{1,2,3,4,5};

Update :

Yes ! this is to be mention that converting an array to an object array OR to use the Object's array is costly and may slow the execution. it happens by the nature of java called autoboxing.

So only for printing purpose, It should not be used. we can make a function which takes an array as parameter and prints the desired format as

public void printArray(int  a){

        //write printing code

} 

In java 8 it is easy. there are two keywords

1. stream: Arrays.stream(intArray).forEach
   


2. 
   

   method reference: ::println

   
   
   

   int intArray = new int {1, 2, 3, 4, 5};
   
   Arrays.stream(intArray).forEach(System.out::println);
   
   

   
   

If you want to print all elements in the array in the same line, then just use print instead of println i.e.

int intArray = new int {1, 2, 3, 4, 5};

Arrays.stream(intArray).forEach(System.out::print);

Another way without method reference just use:

int intArray = new int {1, 2, 3, 4, 5};

System.out.println(Arrays.toString(intArray));

There's one additional way if your array is of type char:

char A = {'a', 'b', 'c'}; 



System.out.println(A); // no other arguments

prints

abc

To add to all the answers, printing the object as a JSON string is also an option.

Using Jackson:

ObjectWriter ow = new ObjectMapper().writer().withDefaultPrettyPrinter();

System.out.println(ow.writeValueAsString(anyArray));

Using Gson:

Gson gson = new Gson();

System.out.println(gson.toJson(anyArray));

A simplified shortcut I've tried is this:

    int x = {1,2,3};

    String printableText = Arrays.toString(x).replaceAll("[\[\]]", "").replaceAll(", ", "n");

    System.out.println(printableText);

It will print

1

2

3

No loops required in this approach and it is best for small arrays only

You could loop through the array, printing out each item, as you loop. For example:

String items = {"item 1", "item 2", "item 3"};



for(int i = 0; i < items.length; i++) {



    System.out.println(items[i]);



}

Output:

item 1

item 2

item 3

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);

     }

public class printer {



    public static void main(String args) {

        String a = new String[4];

        Scanner sc = new Scanner(System.in);

        System.out.println("enter the data");

        for (int i = 0; i < 4; i++) {

            a[i] = sc.nextLine();

        }

        System.out.println("the entered data is");

        for (String i : a) {

            System.out.println(i);

        }

      }

    }

Using org.apache.commons.lang3.StringUtils.join(*) methods can be an option

For example:

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

String arrayAsCSV = StringUtils.join(strArray, " , ");

System.out.printf("[%s]", arrayAsCSV);

//output: [John , Mary , Bob]

I used the following dependency

<groupId>org.apache.commons</groupId>

<artifactId>commons-lang3</artifactId>

<version>3.3.2</version>

For-each loop can also be used to print elements of array:

int array = {1, 2, 3, 4, 5};

for (int i:array)

    System.out.println(i);

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.

// array of primitives:

int intArray = new int {1, 2, 3, 4, 5};



System.out.println(Arrays.toString(intArray));



output: [1, 2, 3, 4, 5]

// array of object references:

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



System.out.println(Arrays.toString(strArray));



output: [John, Mary, Bob]

In java 8 :

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

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 !

If you want to print, evaluate Array content like that you can use Arrays.toString

jshell> String names = {"ram","shyam"};

names ==> String[2] { "ram", "shyam" }



jshell> Arrays.toString(names);

$2 ==> "[ram, shyam]"



jshell>