Regular expression-Registry validation __javascript

Regular Expressions-Registry validation

Regular Expressions
A regular expression is a logical formula for string manipulation, which is a "rule string" that is used to express a filtering logic for a string, using a predefined set of characters and a combination of those particular characters.

The purpose of the regular expression
1. Whether the given string conforms to the filter logic of the regular expression (called "match");
2. A regular expression can be used to get the specific part we want from the string.

regular expressions are characterized by
1. Flexibility, logic and functionality are very strong;
2. The complex control of strings can be achieved quickly and in a very simple way;
3. For those who have just contacted, it is more obscure and difficult to understand.

Registry Validation

1. Get ID

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

2. Verify Name

function CheckName () {
    //Get value
    var username=$ (' user '). Value;
    The judge cannot be an empty
    if (username== ') {
        $ (' s1 '). innerhtml= ' username cannot be empty ';
        return false;
    }
    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 5-10 digits or letters, the beginning cannot be a number ';
        return false;
    }
    Match, return the empty
        $ (' s1 '). innerhtml= ';
        return true;
}
Note: S1 to judge the contents of the prompt, add <span id= ' s1 ' after the input box

3. Verify Password

function Checkpwd () {
    //Get value
        ditto ...
    Judge can not be empty ibid ...
    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 ';
        return false;
    }
    Match, return null
        ibid ...
}

4. Verify the Mailbox

function Checkemail () {
    //Get value
        ditto ...
    Judge can not be empty ibid ...
    Regular expression
    var reg=/^\w+@\w+\.com|cn|net$/;           
    Detects if the input matches the regular expression
    if (!reg.test (email)) {
        $ (' S3 '). innerhtml= ' mailbox illegal ';
        return false;
    }
    Match, return null
        ibid ...
}

5. Verify mobile phone number

function Checktel () {
    //Get value
        ditto ...
    Judge can not be empty ibid ...
    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 illegal ';
        return false;
    }
    Match, return null
        ibid ...
}

6. Verify the ID number

function Checkcid () {
    //Get value
        ditto ...
    Judge can not be empty ibid ...
    Regular expression
    var reg=/^\d{15}$|^\d{17}\d|x$/;         
    Detects if the input matches the regular expression
    if (!reg.test (CID)) {
        $ (' S5 '). innerhtml= ' id not legal ';
        return false;
    }
    Match, return null
        ibid ...
}

7. Verify QQ number

function Checkqq () {
    //Get value
        ditto ...
    Judge can not be empty ibid ...
    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 consist of 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, the jquery Validate validation framework can be used to express validation in the later stages, making it more convenient.