What s the simplest way to print a Java array

Question

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

User · Answer

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  lt  intArray length  i         System out print intArray i               It gives output as yours     1  2  3  4  5

User · Answer

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 lt 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

User · Answer

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

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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

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In java 8 it is easy  there are two keywords   stream  Arrays stream intArray  forEach 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

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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

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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

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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 - gt  System out println s         2 Stream of strArray  forEach System out  println        3 Arrays stream strArray  forEach System out  println       output  John Mary Bob

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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     quot John quot    quot Mary quot    quot Bob quot    System out println Arrays toString array     Output   John  Mary  Bob    Nested Array  String     deepArray   new String        quot John quot    quot Mary quot      quot Alice quot    quot Bob quot     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

User · Answer

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  lt  intArray length  i         System out print intArray i               It gives output as yours     1  2  3  4  5

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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  lt  4  i                  a i    sc nextLine                      System out println  the entered data is            for  String i   a                System out println i

User · Answer

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 lt 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

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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

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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 - gt  Arrays stream x   forEach System out  println       Arrays stream str2DArray  flatMap x - gt  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 lt int   gt  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

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if you are running jdk 8    public static void print int   array        StringJoiner joiner   new StringJoiner                     Arrays stream array  forEach element - gt  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

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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

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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  lt  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 - gt  bytes i   amp  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  lt  bytes2 length  i        bytes2 i     byte  Integer parseInt split i       might need a range check

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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

User · Answer

In java 8 it is easy  there are two keywords   stream  Arrays stream intArray  forEach 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

User · Answer

In java 8    Arrays stream myArray  forEach System out  println

User · Answer

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

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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 - gt  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

User · Answer

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 - gt  Arrays stream x   forEach System out  println       Arrays stream str2DArray  flatMap x - gt  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 lt int   gt  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

User · Answer

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

User · Answer

if you are running jdk 8    public static void print int   array        StringJoiner joiner   new StringJoiner                     Arrays stream array  forEach element - gt  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

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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

User · Answer

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     quot John quot    quot Mary quot    quot Bob quot    System out println Arrays toString array     Output   John  Mary  Bob    Nested Array  String     deepArray   new String        quot John quot    quot Mary quot      quot Alice quot    quot Bob quot     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

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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

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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  lt  items length  i           System out println items i         Output   item 1 item 2 item 3

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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  lt  4  i                  a i    sc nextLine                      System out println  the entered data is            for  String i   a                System out println i

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Here a possible printing function    public static void printArray  int    array           System out print  quot    quot            for  int i   0  i  lt  array length  i                 System out print  quot   quot    array i     quot    quot                      System out print  quot   quot           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

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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     quot John quot    quot Mary quot    quot Bob quot    System out println Arrays toString array     Output   John  Mary  Bob    Nested Array  String     deepArray   new String        quot John quot    quot Mary quot      quot Alice quot    quot Bob quot     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

User · Answer

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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for int n  someArray        System out println n

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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

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Different Ways to Print Arrays in Java    Simple Way     List lt String gt  list   new ArrayList lt String gt     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     Using toString    String   array   new String      One    Two    Three    Four     System out println Arrays toString array          Output   One  Two  Three  Four     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

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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

User · Answer

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

User · Answer

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     quot John quot    quot Mary quot    quot Bob quot    System out println Arrays toString array     Output   John  Mary  Bob    Nested Array  String     deepArray   new String        quot John quot    quot Mary quot      quot Alice quot    quot Bob quot     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

User · Answer

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

User · Answer

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

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Here a possible printing function    public static void printArray  int    array           System out print  quot    quot            for  int i   0  i  lt  array length  i                 System out print  quot   quot    array i     quot    quot                      System out print  quot   quot           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

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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

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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

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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

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Different Ways to Print Arrays in Java    Simple Way     List lt String gt  list   new ArrayList lt String gt     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     Using toString    String   array   new String      One    Two    Three    Four     System out println Arrays toString array          Output   One  Two  Three  Four     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

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toString is a way to convert an array to string   Also  you can use   for  int i   0  i  lt  myArray length  i     System out println myArray i              This for loop will enable you to print each value of your array in order

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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    lt groupId gt org apache commons lt  groupId gt   lt artifactId gt commons-lang3 lt  artifactId gt   lt version gt 3 3 2 lt  version gt

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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

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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

User · Answer

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

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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  lt  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 - gt  bytes i   amp  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  lt  bytes2 length  i        bytes2 i     byte  Integer parseInt split i       might need a range check

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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

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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

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for int n  someArray        System out println n

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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 - gt  System out println s         2 Stream of strArray  forEach System out  println        3 Arrays stream strArray  forEach System out  println       output  John Mary Bob

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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    lt groupId gt org apache commons lt  groupId gt   lt artifactId gt commons-lang3 lt  artifactId gt   lt version gt 3 3 2 lt  version gt

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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  lt  items length  i           System out println items i         Output   item 1 item 2 item 3

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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

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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 - gt  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

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In java 8    Arrays stream myArray  forEach System out  println

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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

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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

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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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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

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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

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toString is a way to convert an array to string   Also  you can use   for  int i   0  i  lt  myArray length  i     System out println myArray i              This for loop will enable you to print each value of your array in order

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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

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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

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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

[java] What's the simplest way to print a Java array?

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