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>