Frequently Used metacharacters include:
• Find a single character, except for line breaks and line Terminators;
• \ W matches letters, Chinese characters, numbers, and underlines;
• \ S matches blank characters (including spaces and tabs );
• \ D matches numbers;
• \ B matches the match at the beginning or end of a word;
Common quantifiers include:
• ^ N matches any string starting with n;
• N $ matches any string ending with n;
• N + matches any string containing at least one n;
• N * matches any string containing zero or more n characters;
• N? Matches any string containing zero or one n;
• N {X} matches strings that contain X n sequences;
• N {X, Y} matches strings that contain X or Y n sequences;
A simple example is used to verify the mobile phone number, phone number, and email address:
Javascript code:
Copy codeThe Code is as follows: function isMobile (){
Var mobile = document. getElementById ("mobile_phone ");
Var num = mobile. value;
Var reg =/^ (13 [0-9] | 186 | 188 | 150 | 151 | 158 | 159 | 147) \ d {8} $ /;
If (num = ""){
Alert ("Enter the complete mobile phone number ");
Mobile. focus ();
Return false;
} Else if (reg. test (num )){
Alert ("the entered mobile phone number is in the correct format ");
} Else {
Alert ("enter the correct 11-digit mobile phone number ");
Mobile. focus ();
Return false;
}
}
Function isEmail (){
Var email = document. getElementById ("email ");
Var email_value = email. value;
If (email_value = ""){
Alert ("Enter the complete email address ");
Email. focus ();
Return false;
} Else {
Var reg =/^ [a-zA-Z0-9] (\ w) + @ (\ w) + (\.) + (com | com \. cn | net | cn | net \. cn | org | biz | info | gov \. cn | edu \. cn) $ /;
If (reg. test (email_value )){
Alert ("the entered email address format is correct ");
} Else {
Alert ("enter the correct email format ");
Email. focus ();
Return false;
}
}
}
Function isPhone (){
Var phone = document. getElementById ("phone ");
Var phone_value = phone. value;
If (phone_value = ""){
Alert ("Enter the complete landline number ");
Phone. focus ();
Return false;
} Else {
Var reg =/^ [(]? 0 \ d {2, 3} [)]? \ S * [-]? \ S * \ d {87989898} $/; // The format of 010-01098989898 0712 (8989898) 23343434 010-landline numbers all meet
If (reg. test (phone_value )){
Alert ("the entered landline number is correct ");
} Else {
Alert ("Incorrect landline number format ");
Phone. focus ();
Return false;
}
}
}
Some HTML code:Copy codeThe Code is as follows: <p>
<Label for = "mobile_phone"> mobile phones </label>
<Input type = "text" id = "mobile_phone", name = "mobile_phone" value = "15107105287" type = "codeph" text = "/codeph"/>
<Input type = "button" value = "validate" onclick = "isMobile ()"/>
</P>
<P>
<Label for = "phone"> seat machine </label>
<Input type = "text" id = "phone" name = "phone" value = "027-87767676"/>
<Input type = "button" value = "validate" onclick = "isPhone ()"/>
</P>
<P>
<Label for = "email"> email box </label>
<Input type = "" id = "email" name = "email" value = "zhangchen2397@126.com"/>
<Input type = "button" value = "validate" onclick = "isEmail ()"/>
</P>
