Concatenating elements in an array to a string

Question

I\'m confused a bit. I couldn\'t find the answer anywhere ;(

I\'ve got an String array:

String[] arr = [\"1\", \"2\", \"3\"];

then

Answer 1

Arrays.toString: (from the API, at least for the Object[] version of it)

public static String toString(Object[] a) {
    if (a == null)
        return "null";
    int iMax = a.length - 1;
    if (iMax == -1)
        return "[]";

    StringBuilder b = new StringBuilder();
    b.append('[');
    for (int i = 0; ; i++) {
        b.append(String.valueOf(a[i]));
        if (i == iMax)
            return b.append(']').toString();
        b.append(", ");
    }
}

So that means it inserts the [ at the start, the ] at the end, and the , between elements.

If you want it without those characters: (StringBuilder is faster than the below, but it can't be the small amount of code)

String str = "";
for (String i:arr)
  str += i;
System.out.println(str);

Side note:

String[] arr[3]= [1,2,3] won't compile.

Presumably you wanted: String[] arr = {"1", "2", "3"};