ArrayList

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Introduction to ArrayList

Exercises on ArrayList

Exercise 1

Consider the following text file that contains grades of the students in a certain course

12.5
19.75
11.25
10
15 
13.25
14
9
10
19.75

Write a Java program, that

  • read these grades from a file
  • store every grade into an ArrayList called grades

after storing all elements into the ArrayList, write a method:

  • max (ArrayList grades) that returns the maximum grade from the ArrayList
  • min (ArrayList grades) that returns the minimum grade from the ArrayList
  • average (ArrayList grades) that returns the average grade from the ArrayList
  • remove_duplicate(ArrayList grades) that returns an ArrayList without any duplicate grade. All duplicated grades must be removed.

Test all these functions in a main method.

Solutions of Exercise 1

Exercise 2

Create an ArrayList of String called strList that contains 10 string words. Create a method called search(String keyword, in minLength) that returns an ArrayList of String. The method should return all the words that contain the keyword and have a length no less than minLength. if minLength == -1, then it returns all words with any length