6 examples of 'regex for decimal number upto 2 places' 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*)?$`
65
      : '^(0|[1-9]\\d*)$'
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  );
67
}

3
function decimalPlaces(num) {
4
    var match = ("" + num).match(/(?:\.(\d+))?$/);
5
    /* istanbul ignore if */
6
    if (!match) {
7
        return 0;
8
    }
9
10
    // Number of digits right of decimal point.
11
    return match[1] ? match[1].length : 0;
12
}

71
function decimalPlaces( number ) {
72
	const match = ( '' + number ).match( /(?:\.(\d+))?(?:[eE]([+-]?\d+))?$/ );
73
	if ( ! match ) {
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		return 0;
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	}
76
	return Math.max( 0, ( match[ 1 ] ? match[ 1 ].length : 0 ) - ( match[ 2 ] ? +match[ 2 ] : 0 ) );
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}

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

61
function groupDigits(num) {
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	var ret = "";
63
	while (num.length > 3) {
64
		ret = "." + num.slice(num.length - 3) + ret;
65
		num = num.substring(0, num.length - 3);
66
	}
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	ret = num + ret;
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	return ret;
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}

7
export default function formatDecimal (value: string): string {
8
  // We can do this by adjusting the regx, however for the sake of clarity
9
  // we rather strip and re-add the negative sign in the output
10
  const isNegative = value[0].startsWith('-');
11
  const matched = isNegative
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    ? value.substr(1).match(NUMBER_REGEX)
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    : value.match(NUMBER_REGEX);
14
15
  return matched
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    ? `${isNegative ? '-' : ''}${matched.join(',')}`
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    : value;
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}