Basic knowledge of JavaScript regular expressions

Basic knowledge of JavaScript regular expressions

1 JavaScript regular object creation and usage

declaring JavaScript regular expressions

var recat = new RegExp ("cat");
You can also
var recat =/cat/; Perl Style (recommended)

2 learning the most commonly used test exec match search replace split 6 methods

1 Test checks to see if the specified string exists

var data = "123123";
var recat =/123/gi;
Alert (recat.test (data)); True

Check to see if the character is present G continue to go down I case insensitive

2 Exec return query value

var data = "123123,213,12312,312,3,cat,cat,dsfsdfs,";
var recat =/cat/i;
Alert (recat.exec (data)); Cat

3 Match Gets the query array

var data = "123123,213,12312,312,3,cat,cat,dsfsdfs,";
var recat =/cat/gi;
var arrmactches = Data.match (recat)

for (Var i=0;i < arrmactches.length; i++)
{
Alert (Arrmactches[i]); Cat Cat
}

4 Search to return to a location similar to IndexOf

var data = "123123,213,12312,312,3,cat,cat,dsfsdfs,";
var recat =/cat/gi;
Alert (Data.search (Recat)); 23

5 Replace replacement character using regular substitution

var data = "123123,213,12312,312,3,cat,cat,dsfsdfs,";
var recat =/cat/gi;
Alert (Data.replace (Recat, "libinqq"));

6) split using a regular split array

var data = "123123,213,12312,312,3,cat,cat,dsfsdfs,";
var recat =/,/;
var arrdata = Data.split (recat);

for (var i = 0; i < arrdata.length; i++)
{
Alert (Arrdata[i]);
}

3 Learning under the simple class negative class range class combination class

Simple class
var data = "1LIBINQQ,2LIBINQQ,3LIBINQQ,4LIBINQQ";
var recat =/[123]libinqq/gi;
var arrdata = Data.match (recat);

for (var i = 0; i < arrdata.length; i++)
{
Alert (Arrdata[i]); 1LIBINQQ 2LIBINQQ 3LIBINQQ
}

Negative to Class
var data = "ALIBINQQ,1LIBINQQ,2LIBINQQ,3LIBINQQ,4LIBINQQ"; U0062cf
var recat =/[^a123]libinqq/gi;
var arrdata = Data.match (recat);

for (var i = 0; i < arrdata.length; i++)
{
Alert (Arrdata[i]); 4libinqq
}

Scope class
var data = "Libinqq1,libinqq2,libinqq3,libinqq4,libinqq5"; U0062cf
var recat =/libinqq[2-3]/gi;
var arrdata = Data.match (recat);

for (var i = 0; i < arrdata.length; i++)
{
Alert (Arrdata[i]); LIBINQQ2 libinqq3
}

Combination Class
var data = "a,b,c,w,1,2,3,5"; U0062cf
var recat =/[a-q1-4n]/gi;
var arrdata = Data.match (recat);

for (var i = 0; i < arrdata.length; i++)
{
Alert (Arrdata[i]); A b C 1 2 3
}

JavaScript is used when validating forms

"^-[0-9]*[1-9][0-9]*$"//Negative integer

"^-?d+$"//Integer

"^d+ (. d+)? $"//nonnegative floating-point number (positive floating-point number + 0)

"^ ([0-9]+. [0-9]*[1-9][0-9]*) | ([0-9]*[1-9][0-9]*. [0-9]+) | ([0-9]*[1-9][0-9]*)] $ "//Positive floating-point number

^ ((-d+ (. d+)?) | (0+ (. 0+)?)) $ "//non-positive floating-point number (negative floating-point number + 0)

^ (-([0-9]+. [0-9]*[1-9][0-9]*) | ([0-9]*[1-9][0-9]*. [0-9]+) | ([0-9]*[1-9][0-9]*))] $ "//negative floating-point number

"^ (-?d+) (. d+)? $"//floating-point number

"^[a-za-z]+$"//A string of 26 English letters

"^[a-z]+$"//A string of 26 uppercase letters

"^[a-z]+$"///a string consisting of 26 lowercase letters

"^[a-za-z0-9]+$"//A string of numbers and 26 English letters

"^w+$"//A string of numbers, 26 English letters, or underscores

"^[w-]+ (. [ w-]+) *@[w-]+ (. [ w-]+) +$ "//email address

"^[a-za-z]+://(w+ (-w+) *) (. ( w+ (-w+) *) *) * (? s*)? $ "//url

function Istruename (s)
{
var patrn=/^[a-za-z]{1,30}$/;
if (!patrn.exec (s)) return false
return True
}
}}

Verify password: Can only enter 6-20 letters, numbers, underscores
<pre Class=java name= "code" >function ispasswd (s)
{
var patrn=/^ (W) {6,20}$/;
if (!patrn.exec (s)) return false
return True
}
</PRE>
<BR>
<br>//Check Ordinary telephone, fax number: You can "+" start, in addition to numbers, can contain "-"
<br><pre Class=java name= "code" >function Istel (s)
{
var patrn=/^[+]{0,1} (d) {1,3}[]? ([-]? (d) {1,12}) +$/;
var patrn=/^[+]{0,1} (d) {1,3}[]? ([-]? ((d) | []) {1,12}) +$/;
if (!patrn.exec (s)) return false
return True
}
</PRE>
<BR>
<br>//Check mobile phone number: Must start with a number, in addition to the number, can contain "-"
<br><pre Class=java name= "code" >function Ismobil (s)
{
var patrn=/^[+]{0,1} (d) {1,3}[]? ([-]? ((d) | []) {1,12}) +$/;
if (!patrn.exec (s)) return false
return True
}
</PRE>
<BR>
<br>//Check ZIP code
<br><pre Class=java name= "code" >function Ispostalcode (s)
{
var patrn=/^[a-za-z0-9]{3,12}$/;
var patrn=/^[a-za-z0-9]{3,12}$/;
if (!patrn.exec (s)) return false
return True
}
</PRE>
<BR>
<br>//Check Search Keywords
<br><pre Class=java name= "code" >function Issearch (s)
{
var patrn=/^[^ ' ~!@#$%^&* () +=|\][]{}:; ',. <>/?] {1} [^ ' ~!@$%^& () +=|\]
[]{}:; ',. <>?] {0,19}$/;
if (!patrn.exec (s)) return false
return True
}

function IsIP (s)//by zergling
{
var patrn=/^[0-9.] {1,20}$/;
if (!patrn.exec (s)) return false
return True
}
</PRE>
<BR>
<br><span style= "font-size:18pt" > Regular expression </SPAN>
<br><pre Class=java name= "code" > "^\d+$"//non-negative Integer (positive integer + 0)
"^[0-9]*[1-9][0-9]*$"//Positive integer
"^ ((-\d+) | (0+)) $ "//non-positive integer (negative integer + 0)
"^-[0-9]*[1-9][0-9]*$"//Negative integer
"^-?\d+$"//Integer
"^\d+ (\.\d+)? $"//nonnegative floating-point number (positive float + 0)
"^ ([0-9]+\. [0-9]*[1-9][0-9]*) | ([0-9]*[1-9][0-9]*\. [0-9]+) | ([0-9]*[1-9][0-9]*)] $"
Positive floating-point numbers
"^ ((-\d+ (\.\d+)?) | (0+ (\.0+)) $ "//non-positive floating-point number (negative floating-point number + 0)
^ (-([0-9]+\. [0-9]*[1-9][0-9]*) | ([0-9]*[1-9][0-9]*\. [0-9]+) | ([0-9]*[1-9][0-9]*))] $"
Negative floating-point numbers
"^ (-?\d+) (\.\d+)? $"//floating-point number
"^[a-za-z]+$"//A string of 26 English letters
"^[a-z]+$"//A string of 26 uppercase letters
"^[a-z]+$"///a string consisting of 26 lowercase letters
"^[a-za-z0-9]+$"//A string of numbers and 26 English letters
"^\w+$"//A string of numbers, 26 English letters, or underscores
"^[\w-]+ (\.[ \w-]+) *@[\w-]+ (\.[ \w-]+) +$ "//email address
"^[a-za-z]+://(\w+ (-\w+) *) (\. ( \w+ (-\w+) *)) * (\?\s*) $ "//url
"^[a-za-z0-9_]*$"
</PRE>