ASP Request Object QueryString Collection

The QueryString collection retrieves the values of the variables in the HTTP query string; that is, it retrieves the values encoded after the question mark (?) in an HTTP request. For example, it parses the values sent by a form using the GET method.

Syntax: ASP Request Object QueryString Collection

Request.QueryString(variable)[(index)|.Count]

Parameters: ASP Request Object QueryString Collection

variable

Specifies the name of the variable in the HTTP query string to retrieve.

ASP Request Object QueryString Collection Index

An optional parameter that enables you to retrieve one of multiple values for variable. It can be any integer value in the range 1 to Request.QueryString(variable).Count.

Remarks: ASP Request Object QueryString Collection

The QueryString collection is a parsed version of the QUERY_STRING variable in the ServerVariables collection. It enables you to retrieve the QUERY_STRING variables by name. The value of Request.QueryString(parameter) is an array of all of the values of parameter that occur in QUERY_STRING. You can determine the number of values of a parameter by calling Request.QueryString(parameter).Count. If a variable does not have multiple data sets associated with it, the count is 1. If the variable is not found, the count is 0.

To reference a QueryString variable in one of multiple data sets, you specify a value for index. The index parameter may be any value between 1 and Request.QueryString(variable).Count. If you reference one of multiple QueryString variables without specifying a value for index, the data is returned as a comma-delimited string.

When you use parameters with Request.QueryString, the server parses the parameters sent to the request and returns the specified data. If your application requires unparsed QueryString data, you can retrieve it by calling Request.QueryString without any parameters.

Examples: ASP Request Object QueryString Collection

You can use an iterator to loop through all the data values in a query string. For example, if the following request is sent:

http://NAMES.ASP?Q=Fred&Q=Sally

and NAMES.ASP contained the following script:

For Each item In Request.QueryString("Q")

Response.Write item & "<BR>"

NAMES.ASP would display the following:

Fred

Sally

Instead of using For Each, you can loop through data values in a query string using the Count variable:

For I = 1 To Request.QueryString("Q").Count

Response.Write Request.QueryString("Q")(I) & "<BR>"

The following client request:

/scripts/directory-lookup.asp?name=fred&age=22

results in the QUERY_STRING value:

name=fred&age=22.

The QueryString collection would then contain two members, name and age.

Welcome, <%= Request.QueryString("name") %>.

Your age is <%= Request.QueryString("age") %>.

This script displays:

"Welcome, Fred. Your age is 22."