Can string.format sequence appear in any order

Question

I have a string here,

return  string.Format("/abcXYZ990099/abc.aspx?IDA={0}&Name={1}&Teacher={2}",
                ID, Name, Teacher);

Now because of requirement changed I need to get "abcXYZ990099" from database too, Is it possible to do something like this,

return  string.Format("/{3}/abc.aspx?IDA={0}&Name={1}&Teacher={2}",
                    ID, Name, Teacher, NewPropertyValue);

Answer 1

Yes, you can do that. But I'd re-index the place holders and re-order the params to suit the order they should appear in the returned string, e.g.

return  string.Format("/{0}/abc.aspx?IDA={1}&Name={2}&Teacher={3}",
                    NewPropertyValue, ID, Name, Teacher);

Answer 2

This is perfectly OK, format items can appear in any order in the string.

For example, when format strings are stored as localized resources, the format items might be in a culture-specific order. For example, to display a full name, you could use:

String.Format(Resources.FullNameFormatString, firstName, middleName, lastName)

And the display order might depend on the culture, e.g.:

en-US: "{0} {1} {2}"  // First Middle Last

fr-FR: "{2}, {0} {1}" // Last, First Middle

You might even have a localized version that doesn't use one of the format items (e.g. middle name):

"{2), {0}" // Last, First (middle name not used)

Of course, in your example it probably makes more sense to reorder the items, as others have said.

Answer 3

You can do. But change the order, since the code must be understandable.

string.Format("/{0}/abc.aspx?IDA={1}&Name={2}&Teacher={3}",NewPropertyValue, ID, Name, Teacher);