Common JavaScript Regular Expression Code sorting (1/4)

I want to write a common JavaScript Regular Expression Code for a friend. I have sorted out some of the following code for reference.

Match the ending number
Source: how to use a javascript Regular Expression to retrieve the last number of strings? Thank you.

For example
30CAC0040 fetch 40
3SFASDF92 fetch 92

The regular expression is as follows:/d + $/g uniform number of spaces
Source: Regular Expression matching space

Character keys in a string contain spaces, but the number of spaces may be inconsistent. The number of spaces is changed to one by regular expression.

Example: Blue

Turn to: Blue

Aobert's regular expression:

The Code is as follows:	Copy code
<Script type = "text/javascript"> Var str = "Blue rational thinking" Var reg =/s +/g Str = str. replace (reg ,"") Document. write (str) </Script>

Determines whether a string is composed of digits.
Source: Is there a simple way to judge whether a string is composed of digits?

This regular expression is relatively simple. I wrote a test

 

The Code is as follows:	Copy code
<Script type = "text/javascript"> Function isDigit (str ){ Var reg =/^ d * $ /; Return reg. test (str ); } Var str = "7654321 "; Document. write (isDigit (str )); Var str = "test "; Document. write (isDigit (str )); </Script>

Regular phone number
Source: I want to know the regular expression of the phone number.

: Verify the JS Regular Expression of the phone number.

/^ D {3, 4}-d {7, 8} (-d {3, 4 })? $/The area code must be a number of 3-4 digits. After the area code, use "-" to connect to the phone number.

^ D {3, 4}-7-8 digits

D {} extension number is a 3-4 digit number, which is not required. If yes, it is connected to the phone number "-".

(-D {3, 4 })? Mobile phone number Regular Expression
The mobile phone number for regular expression verification. The preceding 0 value is ignored. The value range is 130-139,150-159. Ignore the first 0 and then judge that it is 11 bits.

Cloeft regular:

/^ 0*(13 | 15) d {9} $/^ 0 * matches any number of 0 at the beginning.

Because the mobile phone number is 13 digits 9 digits, and 15 digits 9 digits, you can use (13 | 15) d {9} to match.

The test code is as follows:

The Code is as follows:	Copy code
Function testReg (reg, str ){ Return reg. test (str ); } Var reg =/^ 0*(13 | 15) d {9} $ /; Var str = '20140901 '; Var str2 = '20140901 '; Var str3 = '20140901 '; Document. write (testReg (reg, str) + '<br/> '); Document. write (testReg (reg, str2) + '<br/> '); Document. write (testReg (reg, str3) + '<br/> ');

Use a regular expression to delete spaces in a string:
Source: Is there any function in js that removes spaces?

The code and test code are as follows:

 

The Code is as follows:

Copy code

<Script type = "text/javascript"> // Delete the white spaces on both sides of the string. Function trim (str ){ Return str. replace (/^ s + | s + $/g ,''); } // Delete the white spaces on the left of the string. Function ltrim (str ){ Return str. replace (/^ s +/g ,''); } // Delete the white space characters on the right of the string. Function rtrim (str ){ Return str. replace (/s + $/g ,''); } // The following is the test code. Var trimTest = "123456789 "; // There is a space between the front and back. Document. write ('length: '+ trimTest. length +' <br/> '); // Before use Document. write ('ltrim length: '+ ltrim (trimTest). length +' <br/> '); // After ltrim is used Document. write ('rtrim length: '+ rtrim (trimTest). length +' <br/> '); // After rtrim is used Document. write ('trim length: '+ trim (trimTest). length +' <br/> '); // After trim is used </Script>

The test results are as follows:

Length: 11
Ltrim length: 10
Rtrim length: 10
Trim length: 9 Limit text box can only enter numbers, decimal points, and so on
Source: text box input restrictions question ????

Only numbers and decimal places can be entered

Var reg =/^ d *.? D {0, 2} $/starts with a number. There are 0 or a decimal point in the middle, and 0 to 2 digits at the end.

Only lowercase English letters and decimal points can be entered, and colons, forward and backward slashes (:./)

Var reg =/[a-z. /\:] +/; a-z contains lowercase letters ,. it is the decimal point, the backslash (/) and the backslash (\) respectively, and the colon. The entire character set and code can be any one, followed by +, 1 or more.

Replace the content before the decimal point with the specified content
Source: returns a regular expression!

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