public class Test0704 {
	
	public static void main(String[] args) {
		//正常程式碼
		String str1 = "333";
		Double dbnum1;
		dbnum1 = Double.parseDouble(str1);
		System.out.println(dbnum1);
		
		//異常程式碼，丟擲：java.lang.NumberFormatException: For input string:
//		String str = "二哥";
//		Double dbnum;
//		dbnum = Double.parseDouble(str);
		
		//解決為：
		Double dbnum2;
		try{
			String str2 = "二哥";
			dbnum2 = Double.parseDouble(str2);
		}catch(NumberFormatException e) {
			dbnum2 = (double) 0;
		}
		
		System.out.println(dbnum2);
		
		//個別情況下可以使用：DecimalFormat 類
	}

}