问题
I have been at this for hours!!!! An update to the assignment states that we need to stop the user input when their values exceed 100. Without rewriting the whole thing, how do I "loop" this in? I know the code is method heavy but it was a requirement for the assignment. I think my brain is just java-soup! Any help would be AWESOME :)
public static void main(String[] args) {
//Use Main Method for gathering input
float input = 1;
// Declare variable for sum
float theSum = 0;
// Declare variable for average
float average = 0;
// Declare variable for counting the number of user inputs
int counter = 0;
/* Initialize the while loop using an input of 0 as a sentinel value
* to exit the loop*/
while (input != 0) {
// Use JOptionPane method to accept input from user
input = Float.parseFloat(
JOptionPane.showInputDialog(
null, "Please enter a number. Enter 0 to quit: "));
// Invoke sum method and pass input and summation to sum method
theSum = (sum(input, theSum));
// Invoke avg method and pass summation and counter to avg
average = (avg(theSum, counter));
// Increment the counter variable
counter++;
}
// Invoke display method and pass summation, average, and counter variables to it
display(theSum, average, counter);
}
public static float sum(float num1, float sum) {
//Add the user's input number to the sum variable
sum += num1;
//Return value of sum variable as new summation variable
return sum;
}
public static float avg(float num1, int num2) {
//Declare and initialize variable for average
float average = 0;
//Calculate average
average = num1 / num2;
//Return value of average variable
return average;
}
public static void display(float sum, float average, int counter) {
/* I am subtracting 1 from variable counter so as not to include the sentinel value
* of 0 that the user had to enter to exit the input loop in the overall count*/
// Display the count, sum, and average to the user
JOptionPane.showMessageDialog(null, "Count = " + (counter - 1) + ", Sum = " + sum + ", Average = " + average);
// Test to see if sum is greater than 100 and if so, display alert to user
if (sum > 100) {
JOptionPane.showMessageDialog(null, "The sum of your numbers is greater than 100!");
}
}
}
if I enter this after counter++ The user gets this message after the 1st input...WHAT AM I DOING WRONG!!!!!!
if (theSum > 100)
break;
JOptionPane.showMessageDialog(null, "The sum of your numbers is greater than 100!");
The problem with the break was that the "JOptionPane.showMessageDialog(null, "The sum of your numbers is greater than 100!");" piece of code was causing some out put issues when placed immediately after the break. Now the trouble is that the average for the sum>100 is outputting the sum, not average. It works fine for the sum<=100...WTH?!?! :)
Heres the code now:
public static void main(String[] args) {
//Use Main Method for gathering input
float input = 1;
// Declare variable for sum
float theSum = 0;
// Declare variable for average
float average = 0;
// Declare variable for counting the number of user inputs
int counter = 0;
/* Initialize the while loop using an input of 0 as a sentinel value
* to exit the loop*/
while (input != 0) {
// Use JOptionPane method to accept input from user
input = Float.parseFloat(
JOptionPane.showInputDialog(
null, "Please enter a number. Enter 0 to quit: "));
// Invoke sum method and pass input and summation to sum method
theSum = (sum(input, theSum));
// Invoke avg method and pass summation and counter to avg
average = (avg(theSum, counter));
// Increment the counter variable
counter++;
if (theSum > 100)
break;
}
// Invoke display method and pass summation, average, and counter variables to it
display(theSum, average, counter);
}
public static float sum(float num1, float sum) {
//Add the user's input number to the sum variable
sum += num1;
//Return value of sum variable as new summation variable
return sum;
}
public static float avg(float num1, int num2) {
//Declare and initialize variable for average
float average = 0;
//Calculate average
average = num1 / num2;
//Return value of average variable
return average;
}
public static void display(float sum, float average, int counter) {
/* I am subtracting 1 from variable counter so as not to include the sentinel value
* of 0 that the user had to enter to exit the input loop in the overall count*/
// Display the count, sum, and average to the user
if (sum >100)
JOptionPane.showMessageDialog(null, "Count = " + (counter) + ", Sum = " + sum + ", Average = " + average);
if (sum <= 100)
JOptionPane.showMessageDialog(null, "Count = " + (counter-1) + ", Sum = " + sum + ", Average = " + average);
}
}
回答1:
Use a break statement in your while loop with a if condition to check the
thesum > 100. Hope this much of hint will help you to get the desired behavior. As you need to calculate the average also, so put the break logic post avg:
while (input != 0) {
// Use JOptionPane method to accept input from user
input = Float.parseFloat(
JOptionPane.showInputDialog(
null, "Please enter a number. Enter 0 to quit: "));
// Invoke sum method and pass input and summation to sum method
theSum = (sum(input, theSum));
// Invoke avg method and pass summation and counter to avg
average = (avg(theSum, counter));
// Increment the counter variable
counter++;
if (theSum > 100)
break;
}
// Invoke display method and pass summation, average, and counter variables to it
display(theSum, average, counter);
回答2:
Change the loop to
do { ... } while (input != 0 && sum < 100);
You don't need to calculate the average until after the loop stops.
来源：https://stackoverflow.com/questions/18797170/how-do-i-get-this-code-to-stop-input-when-the-sum-exceeds-100-and-still-preform