java 数组.pptVIP

Liang, Introduction to Java Programming, Eighth Edition, (c) 2011 Pearson Education, Inc. All rights reserved. 0132130807 第4讲 数组Arrays汪华登桂林电子科技大学计算机科学与工程学院 数组是一种数据结构？ 数据结构（Data Structure） 链表： 特点？ 顺序表： 特点？ 数组属于哪一种？ 特点？ Single Dimensional Arrays一维数组 Introducing Arrays Declaring Array Variables（数组变量的声明） datatype[] arrayRefVar; Example: double[] myList; datatype arrayRefVar[]; // 也可以，但不被推荐 Example: double myList[]; Creating Arrays（生成数组元素） arrayRefVar = new datatype[arraySize]; Example: myList = new double[10]; myList[0] 代表数组中的第一个元素. myList[9]代表数组中的最后一个元素. Declaring and Creatingin One Step（声明和定义一步完成） 形式：datatype[] arrayRefVar = new datatype[arraySize]; 例如： double[] myList = new double[10]; The Length of an Array（获取数组长度） Once an array is created, its size is fixed. It cannot be changed. You can find its size using arrayRefVar.length For example, myList.length returns 10 Default Values（数组元素缺省值） When an array is created, its elements are assigned the default value of 0 for the numeric primitive data types, \u0000 for char types, and false for boolean types. 编译器里检验看看？ Indexed Variables（数组下标） The array elements are accessed through the index. The array indices are 0-based, i.e., it starts from 0 to arrayRefVar.length-1. In the example in Figure 6.1, myList holds ten double values and the indices are from 0 to 9. Each element in the array is represented using the following syntax, known as an indexed variable: arrayRefVar[index]; Using Indexed Variables（下标使用） After an array is created, an indexed variable can be used in the same way as a regular variable. For example, the following code adds the value in myList[0] and myList[1] to myList[2]. myList[2] = myList[0] + myList[1]; Array Initializers（数组初始化） Declaring, creating, initializing in one step: double[] myList = {1.9, 2.9, 3.4, 3.5}; Declaring, creating, initializing Using the Shorthand Notation double[] myList = {1.9, 2.9, 3.4, 3.5}; 等价于下面的语句: double[] myList = new doubl