如何使用Java脚本验证jsp中的文本字段以仅接受点和逗号作为特殊字符

Question

I need to allow only numerics, dot and comma in a text field. If the user enters other special characters an alert needs to be thrown.

Please find below the conditions:

1. The text field should contain atleast one numeric value.
2. It is not mandatory that the text field should contain dot and comma always.

Thanks for your help.

Answer 1

Here is a start for you: http://jsfiddle.net/KLyy8/1/

Unless you tell us the exact specifics we won't know how to write the regular expression. Sounds like you want numbers with thousands separator and decimals. But how many of each? The fiddle above will work for numbers like this...

123,456.79

12,345.6

1,234.56

etc...

validate=function(){
    var str = document.getElementById('test').value;
    var patt = new RegExp("^[0-9]{1,3}\,[0-9]{3}\.[0-9]{1,2}$");
    var res = patt.test(str);
    alert(res);
}

Answer 2

If the field should contain only numeric values with decimal places (for exmaple 3.14 , 112358 or 9,81 ), then you can use only one regex:

function validateString(str){
    if(str.match(^[0-9\.,]+$)){
        return true;
    }else{
        return false;
    }

However if you want to be precise you will probably want to limit the dots and commas to one, if I understand your situation correctly.

Regex for that can look like this

^[0-9]+(\.|,){0,1}[0-9]+$

That means it starts with a number ( ^[0-9]+ ), then it may contain zero or one times one comma or dot ( (\\.|,){0,1} ) and then again ends with a number ( [0-9]+$ ).