Syntax
var variable = new RegExp(pattern, flags)
The RegExp() object represents a regular expression that is used for pattern matching.
The creation of the object takes pattern and flags parameters.
The pattern is a valid regular expression. The flags are either or both g (global) and i (ignore case).
Properties and Methods of the RegExp() Object
Property/Method | Description |
RegExp.$* | Represents multiline |
RegExp.$& | Represents lastmatch |
RegExp.$_ | Represents input |
RegExp.$` | Represents leftContext |
RegExp.$' | Represents rightContext |
RegExp.$+ | Represents lastParen |
RegExp.$1,$2,...$9 | Represents substring of matches |
compile() | Compiles a regular expression |
exec() | Executes the search for a match in a specified string |
global | _Specifies whether to check the expressions against all possible matches |
ignoreCase | Whether case is ignored or not during a string search |
input | String that is matched |
lastIndex | _Specifies the index at which to start matching the next string. |
lastMatch | Last matched characters |
lastParen | The last parenthesized substring match |
leftContext | The substring preceding the most recent match |
multiline | Specifies whether to search on multiple lines |
rightContext | The substring following the most recent match |
source | The string pattern |
test() | Tests for a string match |
<html> <body> <script language="JavaScript"> <!-- function isSSN(str){ // xxx-xx-xxxx var regexp = /^(\d{9}|\d{3}-\d{2}-\d{4})$/; return regexp.test(str); } function checkInput(){ var valid = true; var ssn = document.form1.ssn.value; if (!isSSN (ssn)){ window.alert("Invalid SSN: " + ssn); valid = false; } else{ alert(ssn + " is a valid SSN"); } } --> </script> <form name="form1"> Enter your SSN: <input type="text" size="15" name="ssn"> <br><br> <input type="button" value="Validate SSN" onClick='checkInput()'> <br> </form> </body> </html>
26.7.RegExp Object | ||||
26.7.1. | RegExp() | |||
26.7.2. | RegExp,$* (1) | |||
26.7.3. | RegExp.$& (2) | |||
26.7.4. | RegExp,$_ (3) | |||
26.7.5. | RegExp.$` (4) | |||
26.7.6. | RegExp.$' (5) | |||
26.7.7. | RegExp.$+ (6) | |||
26.7.8. | RegExp.$1,$2,..$9 | |||
26.7.9. | RegExp.compile() | |||
26.7.10. | RegExp.exec() | |||
26.7.11. | RegExp.global | |||
26.7.12. | RegExp.ignoreCase | |||
26.7.13. | RegExp.input | |||
26.7.14. | RegExp.lastIndex | |||
26.7.15. | RegExp.lastMatch | |||
26.7.16. | RegExp.lastParen | |||
26.7.17. | RegExp.leftContext | |||
26.7.18. | RegExp.multiline | |||
26.7.19. | RegExp.rightContext | |||
26.7.20. | RegExp.source | |||
26.7.21. | RegExp.test() |