for...in Statement (JScript 5.6) 

Executes one or more statements for each property of an object, or each element of an array.

for (variable in [object | array])

      statements 

Arguments

• variable
  Required. A variable that can be any property name of object or any element index of an array.

• object, array
  Optional. An object or array over which to iterate.

• statements
  Optional. One or more statements to be executed for each property of object or each element of array. Can be a compound statement.

Remarks

Before each iteration of a loop, variable is assigned the next property name of object or the next element index of array. You can then use it in any of the statements inside the loop to reference the property of object or the element of array.

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. Iterating through an array will be performed in element order, that is, 0, 1, 2, ...

Example

The following example illustrates the use of the for ... in statement with an object used as an associative array.

function ForInDemo(){

   // Create some variables.

   var a, key, s = "";

   // Initialize object.

   a = {"a" : "Athens" , "b" : "Belgrade", "c" : "Cairo"}

   // Iterate the properties.

   for (key in a)   {

      s += a[key] + "&ltBR>";

   }

   return(s);

}

Requirements

Version 5

See Also

Reference

for Statement (JScript 5.6)
while Statement (JScript 5.6)