created 08/13/99

# Chapter 22 Programming Exercises

Many of your programs from previous chapters can be used with file input and output without modification. Pick a few of them and play. Perhaps make a few modifications, such as removing prompts.

## Exercise 1 --- Maximum

Write a program that reads 5 integers from a file, computes their and their maximum and prints these values to the screen. Do this by modifying the summing program from the chapter. Insert a new `int` variable called `max` which you should initialize to the first value in the file. This will call for an extra set of input statements before the loop starts. To compute the maximum you will need an `if` statement nested inside the loop.

## Exercise 2 --- Floating Point Input

Write a program that adds up five floating point numbers input from a file (or from the keyboard.) As always with input from text files, use `readLine()` to get a string of characters. This string must contain only characters that designate a floating point number, like -0.184 or 1.23E+12. Characters that designate an integer, like 412 will also work for floating point input. Recall how to convert a string into a floating point number:

```String lineIn;
double val;
. . .
val  = ( Double.valueOf( lineIn  ) ).doubleValue();
```

You will need to use the `equals()` method of `String`. Set a boolean variable to true or false depending on the user's first input string. There will be an `if` statement inside the loop that determines if a prompt is written.