Regular expression Registry validation notes collation

A regular expression is a logical formula for a string operation, which is a "rule string" that is used to express a filter logic for a string, using predefined specific characters and combinations of those specific characters.

The purpose of regular expressions

1. Whether the given string conforms to the filtering logic of the regular expression (called "match");

2. You can get the specific part we want from the string using a regular expression.

The regular expression is characterized by

1. Flexibility, logic and functionality are very strong;

2. Complex control of strings can be achieved quickly and in a very simple way;

3. For people who have just come into contact, it is more obscure and difficult to understand.

Registry validation

1. Get ID

function $ (ID) {  return document.getElementById (ID);}

2. Verify your Name

function CheckName () {  //Gets the value  var username=$ (' user '). Value;  The judgment cannot be null  if (username== ') {    $ (' s1 '). innerhtml= ' username cannot be empty ';    return false;  }  The regular expression  var reg=/^[a-za-z][a-za-z0-9]{4,9}$/;  Detects if the input matches the regular expression  if (!reg.test (username)) {    $ (' s1 '). innerhtml= ' username must be a 5-10-digit number or letter consisting of a number at the beginning;    return false;  }  Match, return empty    $ (' s1 '). innerhtml= ';    return true;}

Note: S1 for judging the content, add in the input box after <span id= ' s1 ' ></span>

3. Verify the password

function Checkpwd () {  //Get value    ditto  ... Judgment cannot be empty    Ibid  ... The regular expression  var reg=/^\s{6,}$/;  Detects if the input matches the regular expression  if (reg.test (password) ==false) {    $ (' s2 '). innerhtml= ' Password must be more than 6 bits ';    return false;  }  Match, return null    ibid ...}

4. Verify the Mailbox

function Checkemail () {  //Get value    ditto  ... Judgment cannot be empty    Ibid  ... The regular expression  var reg=/^\w+@\w+\.com|cn|net$/;        Detects if the input matches the regular expression  if (!reg.test (email)) {    $ (' S3 '). Innerhtml= ' email is illegal ';    return false;  }  Match, return null    ibid ...}

5. Verify the phone number

function Checktel () {  //Get value    ditto  ... Judgment cannot be empty    Ibid  ... The regular expression  var reg=/^1[34578]\d{9}$/;       Detects if the input matches the regular expression  if (!reg.test (tel)) {    $ (' S4 '). Innerhtml= ' mobile phone number is not legal ';    return false;  }  Match, return null    ibid ...}

6. Verify the ID number

function Checkcid () {  //Get value    ditto  ... Judgment cannot be empty    Ibid  ... The regular expression  var reg=/^\d{15}$|^\d{17}\d|x$/;       Detects if the input matches the regular expression  if (!reg.test (CID)) {    $ (' S5 '). Innerhtml= ' identity card is not legal ';    return false;  }  Match, return null    ibid ...}

7. Verify QQ number

function Checkqq () {  //Get value    ditto  ... Judgment cannot be empty    Ibid  ... The regular expression  var reg=/^[1-9]\d{7,10}$/;       Detects if the input matches the regular expression  if (!reg.test (QQ)) {    $ (' S6 '). Innerhtml= ' QQ must be 8 to 11 digits, the beginning cannot be 0 ';    return false;      }  Match, return null    ibid ...}

8. Detect all Conditions

function Checkall () {  if (CheckName () &&checkpwd () &&checkemail () &&checktel () & &checkcid () &&checkqq ()) {    return true;  } else{    return false;  }}

Of course, it is more convenient to use the jquery Validate validation framework for expression validation at a later stage.

The above content is the regular expression registry verification Note collation, I hope to help everyone.