How to check character and special character in regex javascript (allow input , and .)

Question

var regex = /^(?=.*[_$@])(?=.*[^_$@.])[\w$@]$/;
var text = "12a/d";
console.log(regex.test(text))

it's not working. I want it's allow input only number and float ex: '12.2,2' , '12', '12.2', '2,2'

Thank everyone

Answer 1

I am not clear about your number format examples. Is 12.2,2 two numbers separated by comma? Is 2,2 the German locale representation of a floating number?

Here is a number validation for the English locale with valid and invalid numbers as input:

const input = [
  '0',
  '1',
  '1.',
  '1.2',
  '-1.2',
  '+1.2',
  '.123',
  '123.45',
  '1,123.45',
  '123,123.45',
  '1,123,123.45',
  '', // invalid
  '1-2', // invalid
  '1+', // invalid
  '1x', // invalid
  '1,12.9', // invalid
  '1,1234.9', // invalid
];
const re = /^[+-]?((\d+|\d{1,3}(,\d{3})+)(\.\d*)?|\.\d+)$/
input.forEach(str => {
  console.log( str + ' => ' + re.test(str));
});

Output:

0 => true
1 => true
1. => true
1.2 => true
-1.2 => true
+1.2 => true
.123 => true
123.45 => true
1,123.45 => true
123,123.45 => true
1,123,123.45 => true
 => false
1-2 => false
1+ => false
1x => false
1,12.9 => false
1,1234.9 => false

Explanation of regex:

• ^ -- anchor at beginning of string
• [+-]? -- optional + or -
• ( -- group 1 start
  • ( -- group 2 start
    • \d+ -- 1+ digits
  • | -- logical OR in group 2
    • \d{1,3}(,\d{3})+ -- 1 to 3 digits, followed by 1+ sets of comma and 3 digits
  • ) -- group 2 end
  • (\.\d*)? -- optional dot and 0+ digits
• | -- logical OR in group 1
  • \.\d+ -- a dot an 1+ digits
• ) -- group 1 end
• $ -- anchor at end of string