交换数组中的值和数组的扩容

交换数组中的值和数组的扩容

public class ArrayChange {
    public static void main(String[]args){
        int [] nums = {4,5,8,9,14,};
        //交换数组中的值，先把nums[2]赋值给临时值，再把nums[1]赋值给nums[2]最后再把临时值赋值给nums[1]
        int temp = nums[2];
        nums[2] = nums[1];
        nums[1] = temp;
        for (int i = 0; i < nums.length; i++) {
            System.out.print(nums[i]+",");
        }
    }
}

4,8,5,9,14,
Process finished with exit code 0

public class ArrayExpansion {
    public static void main(String[] args) {
        int[] nums = {1,2,3};
        //新定义一个大数组
        int[] temp = new int[nums.length*2];
        //遍历原数组并拷贝到新定义的大数组中
        for (int i = 0; i < nums.length; i++) {
            temp[i] = nums [i];
        }
        nums = temp;//再把新定义的大数组指向原数组就变相的完成了数组的扩容
        nums[3] = 8;
        for (int i = 0; i < temp.length; i++) {
            System.out.print(nums[i]+",");
        }
    }
}

1,2,3,8,0,0,
Process finished with exit code 0