How to convert an int array to String with toString method in Java [duplicate]

Solution 1:

What you want is the Arrays.toString(int[]) method:

import java.util.Arrays;

int[] array = new int[lnr.getLineNumber() + 1];
int i = 0;

..      

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

There is a static Arrays.toString helper method for every different primitive java type; the one for int[] says this:

public static String toString(int[] a)
Returns a string representation of the contents of the specified array. The string representation consists of a list of the array's elements, enclosed in square brackets ("[]"). Adjacent elements are separated by the characters ", " (a comma followed by a space). Elements are converted to strings as by String.valueOf(int). Returns "null" if a is null.

Solution 2:

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

should be:

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

Solution 3:

Very much agreed with @Patrik M, but the thing with Arrays.toString is that it includes "[" and "]" and "," in the output. So I'll simply use a regex to remove them from outout like this

String strOfInts = Arrays.toString(intArray).replaceAll("\\[|\\]|,|\\s", "");

and now you have a String which can be parsed back to java.lang.Number, for example,

long veryLongNumber = Long.parseLong(intStr);

Or you can use the java 8 streams, if you hate regex,

String strOfInts = Arrays
            .stream(intArray)
            .mapToObj(String::valueOf)
            .reduce((a, b) -> a.concat(",").concat(b))
            .get();

Solution 4:

You can use java.util.Arrays:

String res = Arrays.toString(array);
System.out.println(res);

Output:

[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

Solution 5:

The toString method on an array only prints out the memory address, which you are getting. You have to loop though the array and print out each item by itself

for(int i : array) {
 System.println(i);
}