Nanfeng

Notes on software development, code, and curious ideas

Removing Trailing Zeros from a Numeric String in TypeScript

In
Remove unnecessary zeros after the decimal point while preserving the value as a string.
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function removeTrailingZeros(numberString: string): string {
  const trimmedString = numberString.trim();
  const decimalIndex = trimmedString.indexOf('.');

  if (decimalIndex !== -1) {
    let endIndex = trimmedString.length - 1;

    while (trimmedString[endIndex] === '0') {
      endIndex--;
    }

    if (trimmedString[endIndex] === '.') {
      endIndex--;
    }

    return trimmedString.slice(0, endIndex + 1);
  }

  return trimmedString;
}

console.log(removeTrailingZeros('3.1400')); // "3.14"
console.log(removeTrailingZeros('10.00'));  // "10"
console.log(removeTrailingZeros('5.50'));   // "5.5"

The function trims surrounding whitespace, removes zeros only from the fractional portion, and also removes the decimal point if no fractional digits remain. Unlike converting through Number, this preserves the input as a string and avoids changing large values through floating-point parsing.

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