3 examples of 'regex for decimal number' in JavaScript

61
function getRegex (isDecimal: boolean): RegExp {
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  return new RegExp(
63
    isDecimal
64
      ? `^(0|[1-9]\\d*)(\\${KEYS.DECIMAL}\\d*)?$`
65
      : '^(0|[1-9]\\d*)$'
66
  );
67
}

68
function removeDecimal(num) {
69
  const re = new RegExp('^-?\\d+');
70
  return num.toString().match(re)[0];
71
}

5
public static validate(decimals: number): (control: FormControl) => { pattern: string } | null {
6
  const regExpString: string = `^[0-9]+((\\.|,){1}[0-9]\\d{0,${decimals - 1}})?$`
7
  const regExp: RegExp = new RegExp(regExpString)
8
9
  return (control: FormControl): { pattern: string } | null => {
10
    const stringAmount: string = new BigNumber(control.value).toFixed()
11
    if (stringAmount.match(regExp) === null) {
12
      return { pattern: 'Pattern does not match.' }
13
    }
14
15
    return null
16
  }
17
}