parse static method

num parse(
  1. String? valueStr, {
  2. int fractionDigits = 0,
})

将字符串转换为数字，转换出错抛出异常

valueStr 转换的字符串

The parameter fractionDigits must be an integer satisfying: 0 <= fractionDigits <= 20.

Examples:

NumUtil.parse('0', fractionDigits: 3);  //0.0
NumUtil.parse(null, fractionDigits: 3); //123456789012345.0
NumUtil.parse('4321.12345678', fractionDigits: 3);  //4321.123
NumUtil.parse('4321.12345678', fractionDigits: 5);  //4321.12346
NumUtil.parse('5.25', fractionDigits: 0));  //5

Implementation

static num parse(String? valueStr, {int fractionDigits = 0}) {
  if (valueStr == null || valueStr.isEmpty)
    return fractionDigits == 0
        ? 0
        : double.parse(0.toStringAsFixed(fractionDigits));
  double value = double.parse(valueStr);
  return format(value, fractionDigits: fractionDigits);
}