数组的简单操作

数组的简单操作

public class arrayDemo03 {
    public static void main(String[] args) {
        int[] array = {1,2,3,4,5};

        //打印数组元素
        for (int i = 0; i < array.length; i++) {
            System.out.println(array[i]);
        }

        //计算所有元素的和
        int sum = 0;
        for (int i = 0; i < array.length; i++) {
            sum += array[i];
        }
        System.out.println("数组的和为：" + sum);
        //查找最大元素
        int max = array[0];
        for (int i = 0; i < array.length; i++) {
            if (max < array[i]){
                max = array[i];
            }
        }
        System.out.println("数组中最大元素为" + max);
    }
}

public class arrayDemo04 {
    public static void main(String[] args) {
        int[] arrays = {1,2,3,4,5};
        // for-each 增强型for循环 适合打印输出，不适合造作内部元素
        // 数组名.for 可在idea中自动生成 JDK1.5版本以上才可以实现 无法对下标进行操作
        for (int array : arrays) {
            System.out.println(array);
           }
        printArray(arrays);
        System.out.println();
        int[] result = reverse(arrays);
        for (int i = 0; i < result.length; i++) {
            System.out.print( result[i] + " ");
        }
    }
    // 反转数组
    public static int[] reverse(int[] arrays){
        int [] result = new int[arrays.length];
        for (int i = arrays.length-1,j=0; i < arrays.length && j < arrays.length; i--,j++) {
            result[j] = arrays[i];
        }
        return result;
    }

        //打印数组元素
    public static void printArray(int[] arrays){
        for (int i = 0; i < arrays.length; i++) {
            System.out.print( arrays[i] + " ");
        }
    }

 }