The University of Texas – Pan American CSCI 3328 Object Oriented Programming in C# Chapter 7: Arrays – Exercises Xiang Lian The University of Texas – Pan American Edinburg, TX 78539 lianx@utpa.edu This set of slides is revised from lecture slides of Prof. John Abraham. -- Xiang Lian

Objectives In this chapter, you will do some exercises about: 1-dimenionsal or multidimensional arrays Data manipulations in arrays

Multiple Choices Lists and tables of values with the same data type can be stored in _____. A. variables B. arrays C. indexes D. keywords The _________ statement allows you to iterate through the elements in an array without using a counter. A. for B. each C. for each D. foreach The number that refers to a particular array element is called the element's _______. A. number B. data type C. index D. class An array that uses two indices is referred to as a(n) _____ array. A. 1-dimensional B. 2-dimensional C. matrix D. list Which of the following statements is true to iterate all elements in the array? A. for (int i = 0; i < array.Length; i++) B. for (int i = 1; i < array.Length; i++) C. for (int i = 1; i <= array.Length; i++) D. for (int i = 0; i <= array.Length; i++)

Multiple Choices (cont'd) Use the foreach header _____ to iterate through double array numbers. A. for each (double d=1; d<numbers.Length; d++) B. foreach (double d = 1 in numbers) C. foreach (double d in numbers) D. for each (double d = numbers[]) Command-line arguments are stored in _____. A. string [] args B. string args C. char args D. char [] args Use the expression _____ to receive the total number of arguments in a command line. A. args.length B. args.Length() C. args.GetLength() D. args.Length The indexed array name of one-dimensional array units's element 2 is _______. A. units{1} B. units(2) C. units[0, 2] D. units [1]

Multiple Choices (cont'd) Which of the following sorts array averageRainfall? A. Array(averageRainfall).Sort() B. Sort.Array(averageRainfall) C. Sort(averageRainfall) D. Array.Sort(averageRainfall)

True/False Statements A single array can store values of different types. An array index should normally be of type float. An individual array element that is passed to a method and modified in that method will contain the modified value when the called method completes execution. Command-line arguments are separated by commas.

True/False Statements (cont'd) The declaration of an array of size 11 is as follows: int arr = new int [10]; The modification of an array element is as follows: 10 = arr[0]; The declaration of a 2-dimensional array is as follows: int [ ] arr = new int [20][10]; The declaration of a 10*10 array is as follows: int [,] arr = new int [11, 11]; The linear search in arrays requires elements in a sorted order. The binary search works well for unsorted arrays

Debugging Errors const int array_size = 5; array_size = 10; int [] b = new int [5]; For (int i =0; i<=b.Length; i++) b[i]=1; int [] a = {1, 2, , 4, 5}; b=a; int [,] c={{1,2}, {3, 4}}; c[1][1] = 5;

Debugging Errors (cont'd) int [, ] array = new int [3, 3]; for (int i = 0; i<=3; i++) for (int j=0; j<=3; j++) array [i, j] = i+j;

Write a Program Write a complete program to generate random number between 1 and 99, and output the resulting number to a resultTextBox.

Write a Program (cont'd) Declare an array, numArray, to hold 100 integer numbers Assign random numbers within [1, 100] into this array Sort this array Check whether a number 50 exists in this array using the linear search and foreach statement Output the multiplication of all even integers in this array; if no even numbers exist, then output 1