❮ Scanner Methods
Example
Find an email address in a line of text:
// Create a scanner object Scanner myObj = new Scanner("Please send an email to info@example.com for more details.");
// Get the email address with a pattern String email = myObj.findWithinHorizon("[a-zA-Z]+@[a-zA-Z]+.[a-zA-Z]{2,}", 0);
// Show the email if found
if (email != null) {
System.out.println(email);
} else {
System.out.println("No email found");
}Definition and Usage
The findWithinHorizon() method searches through a specified number of characters for the first match of a regular expression provided by a Pattern object or a string. If a match is not found then it returns null .
The number of characters to search is specified by the horizon parameter, if it is set to zero then it continues searching without limit.
If a match is found the scanner advances to the first character following the match.
Learn more about the regular expressions in our Java RegEx tutorial .
One of the following
public String findWithinHorizon(Pattern
pattern , int
horizon )public String findWithinHorizon(String
pattern , int
horizon )Parameter Values
| Parameter | Description |
|---|---|
| pattern | Required. A string or Pattern object. Specifies the regular expression used in the search. |
| horizon | Required. Specifies a limit for how far ahead to search. If the value is zero then there is no limit. |
Technical Details
| Returns: | A String containing the matched text or null if no match was found. |
|---|---|
| Throws: | IllegalStateException - If the scanner has been closed. IllegalArgumentException - If the horizon parameter is negative. |
❮ Scanner Methods