Microsoft® JScript™
for...in Statement
 Language Reference 
Version 1 

See Also


Description
Executes a statement for each element of an object or array.
Syntax
for (variable in [object | array])
    statement

The for statement syntax has these parts:

Part Description
variable A variable that can hold any of the elements of object.
object, array An object or array over which to iterate.
statement The statement to be executed for each member of object. Can be a compound statement.

Remarks
Before each iteration of a loop, variable is assigned the next element of object. You can then use it in any of the statements inside the loop exactly as if you were using the element of object.

When iterating over an object, there is no way to determine or control the order in which the members of the object are assigned to variable.

The following example illustrates the use of the for ... in statement:

function ForStmDemo()
{
  // Create some variables.
  var a, d, i, s = "";
  d = new ActiveXObject("Scripting.Dictionary");  
  // Add some keys and items
  d.Add ("a", "Athens");
  d.Add ("b", "Belgrade");
  d.Add ("c", "Cairo");
  // Get the items into an array.
  a = (new VBArray(d.Items())).toArray();
  //Iterate the dictionary.
  for (i in a)
  {
     s += a[i] + "\n";
  }
  return(s);
}