檢查你通過了什麼...檢查我的例子。
package general;
public class TestNumberFormat {
public static void main(String[] args){
String addquantity = "40";
String subquantity = "30";
int final_ = Integer.parseInt(addquantity) - Integer.parseInt(subquantity);
System.out.println("PRINT :" + final_);
String addquantity1 = "D40";
String subquantity1 = "D30";
int final1_ = Integer.parseInt(addquantity1) - Integer.parseInt(subquantity1);
System.out.println("PRINT :" + final1_);
}
}
輸出:
PRINT:10
Exception in thread "main" java.lang.NumberFormatException: For input string: "D40"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:580)
at java.lang.Integer.parseInt(Integer.java:615)
at general.TestNumberFormat.main(TestNumberFormat.java:13)
什麼是錯誤? –
java.lang.NumberFormatException:無效int:「null」 –
quantity1和quantity2包含像3,5這樣的整數值 –