java - Getting 0.0's returned from my object -

i have 3 classes, node, hiddenlayer, , inputnode class.

my hiddenlayer , inputnode classes subclasses of node class , share output() method node class (polymorphism).

my question is: why object returning 0's in hiddenlayer class?

attached code:

node.java

public class node {     protected double number;      public double output(){         return number;     } } 

hiddenlayer.java

public class hiddenlayer extends node {      protected node[] input;      public hiddenlayer(node[] nodes) {         this.input = nodes;     }      //some activation functions can called upon.     class activationfunction {          //sigmoid activation function         public double sigmoid(double x) {             return (1.0 / (1 + math.pow(math.e, -x)));         }          public double derivesigmoid(double d){         return d * (1.0 - d);         }          // hyperbolic tan activation function         public double hypertanfunction(double x) {             return (math.pow(math.e, x) - math.pow(math.e, -x)) / (math.pow(math.e, x) + math.pow(math.e, -x));         }          public double derivehypertanfunction(double d){             return (1.0 - math.pow(hypertanfunction(d), 2.0));         }     }      //output method hiddennode class sum input nodes     //a specific hidden node     public double output(){          /*here implementing following function          *  sigma(x[i] * weights[i]) = net          *  pass net hyberbolic tangent function output between -1 1          *  pass net activation function in train method of neural network          */         //store inputs s temp double array.         double[] temparray = new double[input.length];         (int j = 0; j < input.length; j++){             temparray[j] = input[j].output();             system.out.println(temparray[j]);         }         //setup double sum variable represent net         double net = 0;         //setup loop loop on input nodes array hidden node         (int = 0; < temparray.length; i++){             net = net + temparray[i];         }          return net;     }       public static void main(string[] args) {          inputnode node1 = new inputnode(28);         inputnode node2 = new inputnode(0);         inputnode node3 = new inputnode(165);         inputnode node4 = new inputnode(30);         inputnode node5 = new inputnode(0);         inputnode node6 = new inputnode(0);         inputnode node7 = new inputnode(0);          inputnode[] nodes = {node1, node2, node3, node4, node5, node6, node7};          hiddenlayer h1 = new hiddenlayer(nodes);          h1.output();     } } 

inputnode.java

public class inputnode extends node {     //declare double variable represent holding value inputnode     private double value;      public inputnode(double value) {      }     //create method initialize input nodes     public void set(double tempvalue){         this.value = tempvalue;     }      public double get(){         return value;     }      //override method node class     //this method grab sum of input node values.     public double output(){         return number;      } } 

well, far java concerned, you're ever supplying program 0.

take line:

temparray[j] = input[j].output(); 

output 0.0, initial value upon construction 0.0. reason this: output uses field number return value, , since there's in code explicitly assign number value, returning 0.0.

to fix it, depending on logic or desired operation, should initialize either on inputnode's construction...

public inputnode(double value) {     number = value; } 

...or on node's construction - forcing use constructor described above:

public node(double number) {     this.number = number; }  public inputnode(double number) {     super(number); }