Need help declaring a variable within a for loop (Java)

Question

I'm currently working on a program and ran into an error while trying to execute a for loop. I want to declare a variable in the for loop, then break once that variable obtains a certain value, but it returns the error "cannot be resolved to a variable."

Here's my code

int i = -1;
for (; i == -1; i = index)     
{ 
    Scanner scan = new Scanner(System.in);
    System.out.println("Please enter your first and last name");
    String name = scan.nextLine();
    System.out.println("Please enter the cost of your car,"
                     + "\nthe down payment, annual interest rate,"
                     + "\nand the number of years the car is being"
                     + "\nfinanced, in that order.");
    DecimalFormat usd = new DecimalFormat("'$'0.00");
    double cost = scan.nextDouble();
    double rate = scan.nextDouble();
    int years = scan.nextInt();
    System.out.println(name + ","
                   +  "\nyour car costs " + usd.format(cost) + ","
                   +  "\nwith an interest rate of " + usd.format(rate) + ","
                   +  "\nand will be financed annually for " + years + " years."
                   +  "\nIs this correct?");
    String input = scan.nextLine();
    int index = (input.indexOf('y'));
}

I want to run the output segement of my program until the user inputs yes, then the loop breaks.

rgettman · Accepted Answer · 2013-10-09 18:47:41Z

2

The variable index's scope is local to the block of the for loop, but not the for loop itself, so you can't say i = index in your for loop.

You don't need index anyway. Do this:

for (; i == -1;)

or even

while (i == -1)

and at the end...

    i = (input.indexOf('y'));
}

Incidentally, I'm not sure you want input.indexOf('y'); an input of "blatherskyte" will trigger this logic, not just "yes", because there's a y in the input.

answered Oct 9, 2013 at 18:47

rgettman

179k30 gold badges282 silver badges365 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Kaushik Sivakumar Over a year ago

to add to the above answer also handle upper case Y,also what if the user types in "yay" or something like that,that should also be handled

rgettman Over a year ago

@KaushikSivakumar Yes, the mechanism for breaking from the loop should be changed, for the "blatherskyte", "yay", and "Y" reasons.

user · Accepted Answer · 2013-10-09 18:49:47Z

1

Instead of using a for loop, you can do-while(it suits much better for this scenario.

boolean exitLoop= true;
do
{
    //your code here
    exitLoop=  input.equalsIgnoreCase("y");
} while(exitLoop);

answered Oct 9, 2013 at 18:49

user

2911 gold badge3 silver badges16 bronze badges

Comments

Ankit · Accepted Answer · 2013-10-09 18:48:30Z

for indefinite loop, i would prefer while.

boolean isYes = false;
while (!isYes){ 
Scanner scan = new Scanner(System.in);
System.out.println("Please enter your first and last name");
String name = scan.nextLine();
System.out.println("Please enter the cost of your car,"
                     + "\nthe down payment, annual interest rate,"
                     + "\nand the number of years the car is being"
                     + "\nfinanced, in that order.");
DecimalFormat usd = new DecimalFormat("'$'0.00");
double cost = scan.nextDouble();
double rate = scan.nextDouble();
int years = scan.nextInt();
System.out.println(name + ","
                   +  "\nyour car costs " + usd.format(cost) + ","
                   +  "\nwith an interest rate of " + usd.format(rate) + ","
                   +  "\nand will be financed annually for " + years + " years."
                   +  "\nIs this correct?");
String input = scan.nextLine();
isYes = input.equalsIgnoreCase("yes");
}

bstempi · Accepted Answer · 2013-10-09 18:50:25Z

0

You cannot do this. If the variable is declared inside of the loop, then it is re-created every run. In order to be part of the condition for exiting the loop, it must be declared outside of it.

Alternatively, you could use the break keyworkd to end the loop:

// Should we exit?
if(input.indexOf('y') != -1)
    break;

answered Oct 9, 2013 at 18:50

bstempi

2,0431 gold badge16 silver badges27 bronze badges

Comments

BaconCookies · Accepted Answer · 2013-10-09 19:04:16Z

0

Here you want to use a while loop. Usually you can decide which loop to use by saying your logic out loud to yourself, While this variable is(not) (value) do this.

For your problem, initialize the variable outside of the loop, and then set the value inside.

String userInput = null;
while(!userInput.equals("exit"){
  System.out.println("Type exit to quit");
  userInput = scan.nextLine();
}

answered Oct 9, 2013 at 19:04

BaconCookies

842 bronze badges

Collectives™ on Stack Overflow

Need help declaring a variable within a for loop (Java)

5 Answers 5

2 Comments

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

2 Comments

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related