A binding context is an object that holds data that you can reference from your bindings. While applying bindings, Knockout automatically creates and manages a hierarchy of binding contexts. The root level of the hierarchy refers to the viewModel parameter you supplied to ko.applyBindings(viewModel). Then, each time you use a control flow binding such as with or foreach, that creates a child binding context that refers to the nested view model data.

Thanks:-)

public class B { public static void main(String[] args) throws javax.naming.NoInitialContextException { maths mat=new A(); mat.add(); mat.sub(); String name; try { name = new B().getName(); System.out.println(name); } catch (NamingException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public void createName() throws NamingException { Context context = (Context) new InitialContext(); ((InitialContext) context).bind("java:comp/env", "MyApp"); } public String getName() throws NamingException { Context context = (Context) new InitialContext(); return (String) ((InitialContext) context).lookup("java:comp/env"); } }

if i run this program means it will show error give some solution....

error

javax.naming.NoInitialContextException: Failed to create InitialContext using factory specified in hashtable {} [Root exception is java.lang.NullPointerException] at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:238) at javax.naming.InitialContext.initializeDefaultInitCtx(InitialContext.java:322) at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:352) at javax.naming.InitialContext.getURLOrDefaultInitCtx(InitialContext.java:436) at javax.naming.InitialContext.lookup(InitialContext.java:450) at Model.B.getName(B.java:26) at Model.B.main(B.java:13) Caused by: java.lang.NullPointerException at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:230) ... 6 more