JAVA中int與Integer的相互轉換

①int轉Integer

int a = 5;

Integer A = new Integer(a);

或

Integer A = Integer.valueOf(a);

②Integer轉int

Integer A = new Integer(5);

int a = A.intValue();

③int[] 轉Integer[]

int[] arr = {1,2,3,4,5,6,7,8,9,10};

Integer[] Integers = new Integer[arr.length];

for(int i=0;i<arr.length;i++){

    Integers[i] = arr[i];

}

④Integer[]轉int[]

Interger[] Integers = new Integer[]{3,32,321};

for(int i=0;i<Integer.length;i++）{

    arr[i] = Integer[i].intValue();

}