An efficient, organized approach is needed. Java and most other high-level languages provide a data structure, the array, which stores a fixed-size sequential collection of elements of the same type. In the present case, you can store all 100 numbers into an array and access them through a single array variable. | Chapter 6 Arrays Opening Problem Read one hundred numbers, compute their average, and find out how many numbers are above the average. Solution AnalyzeNumbers Run with prepared input Objectives To describe why arrays are necessary in programming (§). To declare array reference variables and create arrays (§§). To initialize the values in an array (§). To access array elements using indexed variables (§). To declare, create, and initialize an array using an array initializer (§). To program common array operations (displaying arrays, summing all elements, finding min and max elements, random shuffling, shifting elements) (§). To simplify programming using the for-each loops (§). To apply arrays in the LottoNumbers and DeckOfCards problems (§§). To copy contents from one array to another (§). To develop and invoke methods with array arguments and return value (§–). To define a method with variable-length argument list (§). To search elements using the linear (§) or binary (§) search algorithm. To sort an array using the selection sort (§) To sort an array using the insertion sort algorithm (§). To use the methods in the Arrays class (§). Introducing Arrays Array is a data structure that represents a collection of the same types of data. Declaring Array Variables datatype[] arrayRefVar; Example: double[] myList; datatype arrayRefVar[]; // This style is allowed, but not preferred Example: double myList[]; Creating Arrays arrayRefVar = new datatype[arraySize]; Example: myList = new double[10]; myList[0] references the first element in the array. myList[9] references the last element in the array. Declaring and Creating in One Step datatype[] arrayRefVar = new datatype[arraySize]; double[] myList = new double[10]; datatype arrayRefVar[] = new datatype[arraySize]; double myList[] = new double[10]; The Length of an Array Once an array is created, its size is | Chapter 6 Arrays Opening Problem Read one hundred numbers, compute their average, and find out how many numbers are above the average. Solution AnalyzeNumbers Run with prepared input Objectives To describe why arrays are necessary in programming (§). To declare array reference variables and create arrays (§§). To initialize the values in an array (§). To access array elements using indexed variables (§). To declare, create, and initialize an array using an array initializer (§). To program common array operations (displaying arrays, summing all elements, finding min and max elements, random shuffling, shifting elements) (§). To simplify programming using the for-each loops (§). To apply arrays in the LottoNumbers and DeckOfCards problems (§§). To copy contents from one array to another (§). To develop and invoke methods with array arguments and return value (§–). To define a method with variable-length argument list .
