如何检查字符串是否符合美国货币的模式？

^\$?(\d{1,3}(,\d{3})*|(\d+))(\.\d{2})?$

function isUSCurrency(str) {
  var pattern = /^\$?(\d{1,3}(,\d{3})*|(\d+))(\.\d{2})?$/;
  return pattern.test(str);
}

var currency1 = "$1,234.56";
var currency2 = "1,234.56";
var currency3 = "$1234";
var currency4 = "1234.56";
var currency5 = "$1,234.567";

console.log(isUSCurrency(currency1)); // true
console.log(isUSCurrency(currency2)); // true
console.log(isUSCurrency(currency3)); // true
console.log(isUSCurrency(currency4)); // true
console.log(isUSCurrency(currency5)); // false