Angular 7：如何获取区域设置的千位分隔符与小数标记字符

Great question! Parsing a formatted currency string to extract these separators works, but there are more reliable, direct approaches that avoid potential edge cases (like currency symbols or extra formatting characters messing up your extraction). Here are my top recommendations:

1. Use Intl.NumberFormat.formatToParts() (Most Reliable) #

This method returns a structured array of the formatted number's components, so you can directly grab the group (thousand separator) and decimal marker without string parsing hacks.

function getLocaleSeparators(locale) {
  const formatter = new Intl.NumberFormat(locale);
  // Format a number that includes both a thousand separator and decimal point
  const parts = formatter.formatToParts(1234.56);
  
  const thousandSep = parts.find(part => part.type === 'group')?.value;
  const decimalSep = parts.find(part => part.type === 'decimal')?.value;
  
  return { thousandSeparator: thousandSep, decimalSeparator: decimalSep };
}

// Example usage
const usSeparators = getLocaleSeparators('en-US');
console.log(usSeparators); // { thousandSeparator: ',', decimalSeparator: '.' }

const germanSeparators = getLocaleSeparators('de-DE');
console.log(germanSeparators); // { thousandSeparator: '.', decimalSeparator: ',' }

The formatToParts() method eliminates guesswork—you don't have to worry about currency symbols, spacing, or other locale-specific formatting throwing off your string extraction.

2. Leverage Intl.NumberFormat.resolvedOptions() + Targeted Formatting #

If you prefer a slightly more lightweight approach (though not as explicit as formatToParts()), you can combine resolved options with formatting a test number to isolate the separators:

function getSeparatorsFromResolvedOptions(locale) {
  const formatter = new Intl.NumberFormat(locale);
  // Format a number that will definitely include a thousand separator
  const thousandTest = formatter.format(1000);
  // The separator is the character between the first and second digit group
  const thousandSep = thousandTest.slice(1, 2);
  
  // Format a decimal number to get the decimal marker
  const decimalTest = formatter.format(0.1);
  const decimalSep = decimalTest.slice(1, 2);
  
  return { thousandSeparator: thousandSep, decimalSeparator: decimalSep };
}

This works because 1000 will always format into something like 1,000 or 1.000, so the second character is the thousand separator. Similarly, 0.1 becomes 0,1 or 0.1, so the second character is the decimal marker.

Why These Are Better Than Parsing Currency Strings #

Your original approach using formatCurrency() works, but it introduces unnecessary complexity:

• Currency strings often include symbols (like $ or €) or spacing that you'd have to strip out first.
• Some locales format currency with different groupings or decimal rules than plain numbers (though rare, it's a potential edge case).
• The methods above focus directly on number formatting rules, which are exactly what you need for separators.

内容的提问来源于stack exchange，提问作者Torben Vesterager