ToString does not work - tostring

Question

Why toString doesn´t work in my code? The output should be all elements that are in the idChild[].
Error:
child[Ljava.lang.String;#15db9742
public String[] onePointCrossover(int father, int mother) {
String linha1 = individualID.get(father);
idFather = linha1.split(" ");
String linha2 = individualDep.get(father);
depenFather= linha2.split(" ");
String linha3 = individualHour.get(father);
hourFather = linha3.split(" ");
String linhaA = individualID.get(mother);
idMother = linha1.split(" ");
String linhaB = individualDep.get(mother);
depenMother= linha2.split(" ");
String linhaC = individualHour.get(mother);
hourMother = linha3.split(" ");
String [] idChild = new String [idFather.length];
int crossPoint = (int) (Math.random()*idFather.length);
for(int i=0; i<idFather.length; i++)
{
if (i<crossPoint)
idChild[i] = idFather[i];
else
idChild [i] = idMother[i];
}
System.out.println("child" + idChild.toString());
return idChild;
}

Answer 1

If you want to loop through all childs in your array, then you need to loop through it, other wise you are attempting to read an array of objects as a string!
Try:
foreach (string s in idChild)
{
System.out.println(s);
}

Answer 2

This is the way toString() works (documentation here): the default implementation of the Object class (and of all arrays) shows the class name, the # symbol and the hexadecimal representation of the hash code of the object:
public String toString() {
return getClass().getName() + "#" + Integer.toHexString(hashCode());
}
The documentation says:
Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object.
So it's really up to the programmer to choose what "textually represents" means.
If you want to print the String representation of all the items in an array you have to iterate over it.