[英]Creating factorial - if, else statement with error messages in java
我需要使用if,else語句創建階乘代碼,其中用戶輸入的絕對數字必須大於零。 否則,它將顯示一條錯誤消息,要求用戶輸入大於零的整數。 我從以下代碼開始:
System.out.print("Enter your number: ");
int number = sc.nextInt();
if (number<=0)
{
for (count=1; count<=number; count++)
factorial = factorial*count;
System.out.println("Factorial of your number is: "+factorial);
System.out.println();
}
else
{
System.out.println("Enter a positive whole number greater than 0");
System.out.println();
}
該代碼對於輸入零或負數的階乘和錯誤消息運行正常。 因此,我唯一需要的是為錯誤消息定義整個編號。
看來,侑是把錯誤的condion的,如果循環的number
作為if(number<=0)
將采取所有數量小於或等於0,但按你的條件,你要大於0的數字,因此改變代碼如下:
try{
System.out.print("Enter your number: ");
int number=sc.nextInt();
}catch(Exception ex) {
System.out.pritnln("please enter a valid number");
ex.printStackTrace();
}
if (number>0)
{
for (count=1; count<=number; count++)
factorial = factorial*count;
System.out.println("Factorial of your number is: "+factorial);
System.out.println();
}
else
{
System.out.println("Enter a positive whole number greater than 0");
}
只需在對nextInt()
調用周圍放置一個try
塊,然后如果引發異常,請告訴用戶,如下所示:
int number = 0;
boolean ok = true;
try {
number = sc.nextInt();
} catch (Exception ex) { //user did not enter a valid integer
ok = false;
}
if (number>0 && ok) {
//...
} else {
System.out.println("Enter a positive whole number greater than 0");
}
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