数组的基本操作

数组的基本操作

代码如下：

package ClassDemo; public class TestArray { public static void main(String[] args) {
// testWork01();

// testWork02();

// 1.使用scanner输入值初始化数组
double[] myList = new double[5];
java.util.Scanner sc = new java.util.Scanner(System.in);
System.out.println("请输入 " + myList.length + " 个值");
for (int i = 0; i < myList.length; i++) {
myList[i] = sc.nextDouble();
} // 2.使用随机数初始化数组
// double[] myList = new double[10];
// for (int i = 0; i < myList.length; i++) {
// myList[i] = Math.random() * 100;
// }

// 3.打印数组
for (int i = 0; i < myList.length; i++) {
System.out.println(myList[i]);
}
// 4.对所有元素求和
double total = 0;
for (int i = 0; i < myList.length; i++) {
total += myList[i];
}
System.out.println("The sum of the array is: " + total);
// 5.找出最大元素
double max = myList[0];
for (int i = 1; i < myList.length; i++) {
if (max < myList[i]) {
max = myList[i];
}
}
System.out.println("The max value of the array is: " + max);
// 6.找出第一个最大元素的下标值
double max1 = myList[0];
int indexOfMax = -1;
for (int i = 1; i < myList.length; i++) {
if (max1 < myList[i]) {
max1 = myList[i];
indexOfMax = i;
}
}
System.out.println("The index of max in the array is: " + indexOfMax);
// 7.随意打乱（shuffling）
for (int i = 0; i < myList.length; i++) {
int index = (int) (Math.random() * myList.length);
// 将myList[index]和myList[i]互换
double tempVar = myList[i];
myList[i] = myList[index];
myList[index] = tempVar;
}
// 8.向左循环移动数组中的元素 } private static void testWork02() {
// double[] myList = {5.6, 4.5, 3.3};

double[] myList = new double[3];
myList [0] = 5.6;
myList [1] = 4.5;
myList [2] = 3.3;
for (int i = 0; i < myList.length; i++) {
System.out.println(myList[i]);
}
} private static void testWork01() {
final int NUMBER_OF_ELEMENTS = 10;
int[] numbers = new int[NUMBER_OF_ELEMENTS];
for (int i = 0; i < numbers.length; i++) {
numbers[i] = i;
}
for (int i = 0; i < NUMBER_OF_ELEMENTS; i++) {
System.out.println(numbers[i]);
}
} }

希望能够有所帮助