JavaScript Regular Expression-based numeric judgment Function

1. The following lists some regular expressions that interpret numeric types.
Copy codeThe Code is as follows:
"^ \ 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 + )? $ "// Non-negative 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

2. usage in the program
Copy codeThe Code is as follows:
Var r =/^ [0-9] * [1-9] [0-9] * $ // positive integer
R. test (str); // str returns true or false for the characters to be judged.

3. Test a regular expression function, which can be used to determine the js function of the number character date Email.
Copy codeThe Code is as follows:
Function TestRgexp (re, s) {// parameter description re is the regular expression s is the character to be judged
Return re. test (s)
}

4. function applications
Copy codeThe Code is as follows:
<Script type = "text/javascript">
Function TestRgexp (re, s) {// parameter description re is the regular expression s is the character to be judged
Return re. test (s)
}
Var re =/^ [0-9] * [1-9] [0-9] * $ /;
// Determine whether the expression is a positive integer. Note: Regular Expression format in the program:/the regular expression above (without double quotation marks )/
Var s = prompt ("Enter the character to be judged", 10 );
Var result = TestRgexp (re, s); // return true or false for the test
Alert (result );
</Script>