A Simple Method for JavaScript to obtain URL parameters (querystring)

It is not difficult to obtain URL parameter information through JavaScript, and there are many methods. The reason for using this method is that it uses regular expressions and is very concise.

2. FunctionGetquery (name)
4. {
6. VaRReg =NewRegexp ("(^ | &)"+ Name +"= ([^ &] *) (& | $ )");
8. VaRR = Window. Location. Search. substr (1). Match (REG );
10. If(R! =Null)
12. ReturnUnescape (R [2]);
14. Return Null;
16. }

For example, you need to use JavaScript to display different error messages on the page based on different values of the URL parameter errtype:

2. <Div ID="Diverror" Style="Color: red; font-weight: bold; text-align: center; width: 100%; Height: 300px; padding-top: 30px ;"></Div>
6. <Script Language="JavaScript">
10. // Define the descriptions of errors
12. VaRErrinfos= {"1": "The submitting user shoshould not be allowed to review his submissions ",
14. "2": "reviewers cannot review the same submission twice ",
16. "3": "Only people in the" reviewers "group shocould be able to access the Review Form"
18. }
22. Function getquery (name)
24. {
26. VaRReg=NewRegexp ("(^ | &)" + name + "= ([^ &] *) (& | $ )");
28. VaRR=Window. Location. Search. substr (1). Match (REG );
30. If (R! = NULL)
32. Return Unescape (R [2]);
34. Return NULL;
36. }
40. VaRErrtype=Getquery("Errtype ")
42. If (errtype)
44. Document. getelementbyid ("diverror "). Innertext=Errinfos[Errtype]
46. </Script>