读取输入到一行

Question

Allow me provide more information with what I'm having trouble with. Say I have some code

int a;
System.out.print(Enter a number ");
a = keyboard.nextInt

The first statement will be

Enter a number

the user then enters a number, say 12, the final statement is

Enter a number 12

Notice how this is all on one line. Im trying to do the same thing, but with a float and I want it to only show 2 digits after the decimal. I tried

float money;
System.out.printf("Enter your money " + "%.2f\n", money);
money = keyboard.nextFloat();

but I get an error saying money hasn't been initialized. However, if I write

float money = 0.0f;
System.out.printf("%.2f\n", money + "Enter your money ");
money = keyboard.nextFloat();

The output isn't what I want, its

Enter your money 0.00

The user then enters their money, say 1234.567. The final output is

Enter your money 0.00
1234.58

So, how can I display 1234.58 so that the final output is

Enter your money 1234.58

Answer 1

The user will always see what the user types. You can't hide that.

When you first prompt, the user sees ( _ for cursor):

Enter your money _

When a user then types a number, and presses enter, the display is:

Enter your money 3.14159
_

As you can see, the cursor is already at the next line. You can't change the first line at this point. You can print another line, but the first one will always be there, eg

System.out.printf("You entered %.2f%n", money);

will give the following result:

Enter your money 3.14159
You entered 3.14
_

Answer 2

System.out.print("Enter your money ");
float money = keyboard.nextFloat();
System.out.printf("%.2f", money);

EDIT

You want an explanation so I will give it to you :D As java API states System.out.print method will print string to the console without entering new line. So you will get "Enter your money" string on the screen without newline . After user input keyboard.nextFloat() the rest of the string will be put on the string with System.out.printf("%.2f", money) .