Introduction to the use of javascript practical small Functions

1. prevent non-numeric input, except for backspace
Copy codeThe Code is as follows:
<Script type = "text/javascript">
Var checkNo = function (e ){
Var keyCode = e. charCode? E. which: e. keyCode;
If (keyCode = 8 ){
Return true;
}
Var realkey = String. fromCharCode (keyCode );
Var reg = "\ d ";
Var regExp = new RegExp (reg );
Return regExp. test (realkey );
}
</Script>

2. Restrict the maximum length of the input string
Copy codeThe Code is as follows:
// Limit the maximum input length
Var checkMaxL = function (length ){
Var regC =/[^-~] +/G;
Var regE =/\ D +/g;
Var str = jQuery ("# remark"). val ();

If (regC. test (str )){
JQuery ("# remark"). val (str. substring (0, length ));
}

If (regE. test (str )){
JQuery ("# remark"). val (str. substring (0, length ));
}
}