{"id":302,"date":"2012-08-02T07:38:17","date_gmt":"2012-08-02T14:38:17","guid":{"rendered":"http:\/\/blogs.unsw.edu.au\/infs1609\/?p=302"},"modified":"2012-08-02T08:02:27","modified_gmt":"2012-08-02T15:02:27","slug":"lab-week-4-loops-and-arrays","status":"publish","type":"post","link":"https:\/\/blogs.unsw.edu.au\/infs1609\/blog\/2012\/08\/lab-week-4-loops-and-arrays\/","title":{"rendered":"Lab Week 4 – Loops and Arrays"},"content":{"rendered":"

This week, you will download the BlueJ project Week4.zip<\/a> and write methods to manipulate arrays. Two methods are given to you complete. You don’t have to do anything to them.<\/p>\n

The method readArray<\/strong><\/p>\n

public int[] readArray()<\/code><\/p>\n

reads a list of numbers, one per line, ending with a blank line, and returns an array containing the numbers. Don’t try to understand the details of this method. It uses things that you’ll learn about later.<\/em><\/p>\n

The method printArray<\/strong> takes an integer array parameter and prints it to the terminal<\/p>\n

public void printArray(int[] R)<\/code><\/p>\n

The project provides templates for other methods that you have to write. Your job is to work out the code that goes inside them.<\/p>\n

The first method, arrayAdd<\/strong>, takes two arrays as parameters and returns a new array that is the sum of the first two.<\/p>\n

public int[] arrayAdd(int[] R1, int[] R2)<\/code><\/p>\n

The addition of two arrays yields an array whose elements are the sum of the corresponding elements in the parameter arrays, i.e.<\/p>\n

R1[0] + R2[0],\u00a0R1[1] + R2[1],\u00a0R1[2] + R2[2], ....<\/code><\/p>\n

The dotProduct<\/strong> of two arrays returns a single integer.<\/p>\n

public int dotProduct(int[] R1, int[] R2)<\/code><\/p>\n

It is found by multiplying corresponding elements and adding them all up, i.e.<\/p>\n

R1[0] * R2[0] +\u00a0R1[1] * R2[1] + R1[2] * R2[2], ....<\/code><\/p>\n

Finally, you should write a method, main<\/strong>,<\/p>\n

public void main()<\/code><\/p>\n

that reads two arrays, then:<\/p>\n