Arrays. Structure programming. Section-(6) Array Initialization. <Type> [] identifier;

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1 El-Shorouk Academy Acad. Year : 2013 / 2014 Higher Institute for Computer & Term : Second Information Technology Year : First Department of Computer Science <Type> [] identifier; Structure programming Section-(6) Arrays The initial value of an array is null. An array object is created using new: int[] store = new int[50]; string[] names = new string[50]; For the store array, each element is an int with the value 0. For the names array, each element is a string with the value null. // Declare a single-dimensional array int[] array1 = new int[5]; // Declare and set array element values int[] array2 = new int[] 1, 3, 5, 7, 9 ; // Alternative syntax int[] array3 = 1, 2, 3, 4, 5, 6 ; // Declare a two dimensional array int[,] multidimensionalarray1 = new int[2, 3]; // Declare and set array element values int[,] multidimensionalarray2 = 1, 2, 3, 4, 5, 6 ; // Declare a jagged array int[][] jaggedarray = new int[6][]; // Set the values of the first array in the jagged array structure jaggedarray[0] = new int[4] 1, 2, 3, 4 ; Array Initialization int[] store = 0, 1, 2, 3, 10, 12; int[] store = 0, 1, 2, 3, 10, 12 ; Console.WriteLine(store[4]); Page 1 of 6

2 int[] store = new int[6] 0, 1, 2, 3, 10, 12; // print value of element int[] store = new int[6] 0, 1, 2, 3, 10, 12 ; Console.WriteLine(store[4]); // print values of array int[] store = new int[6] 0, 1, 2, 3, 10, 12 ; for (int i = 0; i < store.length; i++) Console.WriteLine(i+""+store[i]); Array Initialization int[] numbers = new int[5] 1, 2, 3, 4, 5; int[] numbers = new int[] 1, 2, 3, 4, 5; int[] numbers = 1, 2, 3, 4, 5; string[] names = new string[3] "Matt", "Joanne", "Robert"; string[] names = new string[] "Matt", "Joanne", "Robert"; string[] names = "Matt", "Joanne", "Robert"; Example: string [] names =new string []"asmaa","amr","heba","ahmed","aly"; Console.WriteLine(names[3]); //for print array for (int i = 0; i <names.length; i++) Console.WriteLine(names[i]); Notes : for (int i = 0; i <=names.length-1; i++) Console.WriteLine(names[i]); Example (array +for each) int[] numbers = 4, 5, 6, 1, 2, 3, -2, -1, 0 ; foreach (int i in numbers) Console.WriteLine(i); int[] numbers = 4, 5, 6, 1, 2, 3, -2, -1, 0 ; for (int i =0;i<numbers.Length;i++) Console.WriteLine(i+" "+numbers[i]); Example : print values of array taken from user Page 2 of 6

3 int n; Console.Write("Enter The Number Of Elements = "); n = int.parse(console.readline()); int[] A = new int[n]; Console.WriteLine("Enter Values"); A[i] = int.parse(console.readline()); Console.WriteLine("The Values Are :-"); Console.WriteLine("A[" + i + "]=" + A[i]); Example : print the sum of array int sum = 0; int[] A = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ; sum += A[i]; Console.WriteLine("Sum Of Array Elements = " + sum); Example:print the sum of decimal number of array Console.WriteLine(" enter size of array"); int x=int.parse(console.readline()); float[] a = new float[x]; float sum = 0; for (int i = 0; i < a.length; i++) a[i] = float.parse(console.readline()); sum += a[i]; Console.WriteLine("Sum Of Array Elements = " + sum); Example : print the avaerge of an array Console.WriteLine(" enter size of array"); int x=int.parse(console.readline()); float[] a = new float[x]; float sum = 0; for (int i = 0; i < a.length; i++) a[i] = float.parse(console.readline()); sum += a[i]; int count =a.length; float avg = sum / count; Console.WriteLine("Sum Of Array Elements = " + sum); Console.WriteLine("count Of Array Elements = " + count); Console.WriteLine("avg Of Array Elements = " + avg); Page 3 of 6

4 Example : print max,min of numbers from user Console.Write("Enter The Number Of Elements = "); int n = int.parse(console.readline()); int[] A = new int[n]; Console.WriteLine("Enter Values"); for ( int i = 0; i < A.Length; i++) A[i] = int.parse(console.readline()); Console.WriteLine("The Values Are :-"); foreach (int j in A) Console.WriteLine("A[" + j + "]=" + j); int index1 = 0, index2 = 0; int max = A[0]; int min = A[0]; if (max < A[i]) max = A[i]; index1 = i; if (min > A[i]) min = A[i]; index2 = i; Console.WriteLine("Max = " + max + "\t" + "At Position : " + index1); Console.WriteLine("Min = " + min + "\t" + "At Position : " + index2); Example: searching for an element in array int n, x, i, flag =0; Console.Write("Enter The Number Of Elements = "); n = int.parse(console.readline()); int[] A = new int[n]; Console.WriteLine("Enter The Elements"); for (i = 0; i < A.Length; i++) A[i] = int.parse(console.readline()); Console.Write("Enter The Element You Search For = "); x = int.parse(console.readline()); for (i = 0; i < A.Length; i++) if (x == A[i]) Console.WriteLine("Found At Pos : " + i); flag = 1; if (flag == 0) Console.WriteLine("Not Found!!"); Page 4 of 6

5 int[] A =100,5,-30,67,35,10,-40; int max = A[0]; int min = A[0]; if (max <= A[i]) max = A[i]; if (min > =A[i]) min = A[i]; Console.WriteLine("the max is " + max); Console.WriteLine("the min is " + min); Example: Write a program that creates three arrays of different data types. Fill in the three arrays with arbitrary data from your choice, and then print the elements of the three arrays using 3 different Repetition Structure int[] a = 6, 8, 3, 9, 0 ; double[] b = 6.8, 8.2, 3.1, 9, 0.4 ; char[] c = '6', 'a', '*', 'G', '^' ; string [] e="asp.net","c","c++","php","java"; for (int i = 0; i <5 ; i++) Console.WriteLine(a[i]); Console.WriteLine(b[i]); Console.WriteLine(c[i]); Console.WriteLine(e[i]); Console.WriteLine(); int k = 0; while (k < 5) Console.WriteLine(a[k]); Console.WriteLine(b[k]); Console.WriteLine(c[k]); Console.WriteLine(e[k]); k++; int j = 0; Page 5 of 6

6 do Console.WriteLine(a[j]); Console.WriteLine(b[j]); Console.WriteLine(c[j]); Console.WriteLine(e[j]); j++; while (j < 5); Example: Define an array A with any number of integers (say 6 integers). Create another array called B of the same length and copy array A to Array B int[] A = 6, 4, 8, 2, 9, 10 ; int[] B = new int[6]; B[i] = A[i]; Console.WriteLine(B[i]); Page 6 of 6