数字和一位小数的正则表达式

Question

I can't seem to get a simple regular expression to work. Here's what I have at the moment:

$(".Hours").on('input', function (e) {

    var regex = /^\d+(\.\d{0,2})?$/g;

    if (!regex.test(this.value)) {
        if (!regex.test(this.value[0]))
            this.value = this.value.substring(1, this.value.length);
        else
            this.value = this.value.substring(0, this.value.length - 1);
    }
});

I need the user to be able to only enter numbers and one decimal (with only two numbers after the decimal). It's working properly now, with the exception that a user cannot start with a decimal.

Acceptable:

23.53
0.43
1111.43
54335.34
235.23
.53 <--- Not working 

Unacceptable:

0234.32 <--- The user can currently do this
23.453
1.343
.234.23
1.453.23

Any help on this?

Answer 1

Updated answer:

RegExp -

^(?:0|[1-9]\d+|)?(?:.?\d{0,2})?$

Explanation at regex101 :

Original answer:

fiddle Demo

RegExp -

^(\d+)?([.]?\d{0,2})?$

Explanation

Assert position at the beginning of the string «^»
Match the regular expression below and capture its match into backreference number 1 «(\d+)?»
   Between zero and one times, as many times as possible, giving back as needed (greedy) «?»
   Match a single digit 0..9 «\d+»
      Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
Match the regular expression below and capture its match into backreference number 2 «([.]?\d{0,2})?»
   Between zero and one times, as many times as possible, giving back as needed (greedy) «?»
   Match the character “.” «[.]?»
      Between zero and one times, as many times as possible, giving back as needed (greedy) «?»
   Match a single digit 0..9 «\d{0,2}»
      Between zero and 2 times, as many times as possible, giving back as needed (greedy) «{0,2}»
Assert position at the end of the string (or before the line break at the end of the string, if any) «$»

Answer 2

Here is a suggestion : /^((\\d|[1-9]\\d+)(\\.\\d{1,2})?|\\.\\d{1,2})$/ .

Allows : 0 , 0.00 , 100 , 100.1 , 100.10 , .1 , .10 ...

Rejects : 01 , 01.1 , 100. , .100 , . ...

Answer 3

这是否满足您的需求：

var regex = /^\d+([.]?\d{0,2})?$/g;

Answer 4

Your regex: var regex = /^\\d+(\\.\\d{0,2})?$/g;

What you need: var regex = /^\\d*(\\.\\d{1,2})?$/;

You were requiring at least one digit before the decimal ( \\d+ ). I have also changed it so if you include a decimal, there must be at least one digit after it.

Answer 5

This one will force you to add digit after decimal separator :

^\d+([.]\d)?$

Example :

• 123 => true
• 123. => false
• 123.1 => true
• 123.12 => false
• 123.. => false

if you want more digit; 3 for ex; make sure you fix min to "1" for digit after dicimal

^\d+([.]\d{1,3)?$