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average_of_lines

Language/Type: PHP basics streams file input
Author: Melissa Hovik (on 2018/11/22)

Write a function named average_of_lines that accepts a file name as a parameter and reads that file, assumed to be full of real numbers, and returns the average (mean) of the numbers in that file. The parameter, $filename, gives the name of a file that contains a list of real numbers, one per line. You may assume that the file exists and follows the proper format. For example, if a file named input.txt contains the following numbers

1.5
2.75
9.0
-3.25
0.0
6.5

Then the call of average_of_lines("input.txt"); should return 2.75.

You may assume that the input file exists and is in the proper format. If the file does not contain any input values, return 0.0.

Constraints: Your solution should read the file only once, not make multiple passes over the file data.

Type your PHP solution code here:


This is a function exercise. Write a PHP function as described. Do not write a complete program; just the function(s) above.

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