Extract

The Extract function extracts the part of the string in the first parameter that matches the regular expression passed in the second parameter and returns it.

Only the parts of the regular expression that are in parentheses are extracted from the string in the first parameter. When more than one part of the regular expression is in parentheses, the strings returned by each part of the expression are concatenated and returned by the function.

Return type

The function return type is: STRING

Function parameters

Table 1. Extract assignment function parameters
Parameter order	Input variable type	Parameter data type	Required parameter	Description
1	Data field	STRING	Yes	The data field to be searched for the regular expression.
2	Constant	REGEX	Yes	The regular expression used to find and return part of the string in the first parameter.

Examples

The following XML shows an example of using the Extract function in an assignment element.

<assignment field="testExtract" type="Extract" value="ibmNprBdCategory,'([a-z]*)'"/>

In this example, the Extract function is called to return the part of the ibmNprBdCategory string that matches the regular expression ([a-z]*). The value returned by the function is assigned to the testExtract field.

The regular expression in the following example extracts only characters 3 - 5 and characters 9 - 10 from a source string. These two sets of characters are then concatenated and returned by the Extract function.

^\w{2}(\w{3})\d{3}(\w2)

The following table shows examples of the strings that the Extract function returns for this regular expression.

Table 2. Extract data field assignment function examples
Source string	Resulting string	Comments
ABCDE123XY	CDEXY
ABCDE123XYblahblah	CDEXY
ABCDEFGHXY		No characters were extracted because there were no digits in the source string. The regular expression expects characters 6 - 8 to be digits.