allowing input only for float number

Question

I have pain-time when making input that only allows float number with jquery library. my code can\'t prevent chacacter \".\" when it\'s becoming first input, can anyone guid

Answer 1

Regular expression would be my recommendation as well. If the value is being passed as a number and not a string you can use .toString to change it to a string and validate it with regular expression. For example:

var str = value.toString();
if(!str.match(/^-?[0-9]*[.][0-9]+$/)) {
    alert("Value must be a float number");
    return;
}
return value;

The above regex will match if the value passed is a floating point number. It accepts both negative and positive numbers. If you only want to accept positive numbers simply remove the '-?' from the expression. It will also fail if the value is simply zero '0' without any decimal point. If you want to accept zero simply add it as a condition to the 'if' statement.

You can use the above validation and an onchange event to prevent the user from entering a non-flot number.