注：数组一旦被初始化，就没有办法改变他的长度

1、末尾增加元素

int[] ordArray = {1,2,3,4,5};
int[] newArray = new int[ordArray.length+1];

for (int i=0;i<=ordArray.length-1;i++){
    newArray[i]=ordArray[i];
}
newArray[newArray.length-1]=0;
for (int x:newArray){
    System.out.println(x);
}

2、指定位置添加元素

int[] ordArray = {1,2,3,4,5};
int[] newArray = new int[ordArray.length+1];

for (int i=0;i<=newArray.length-1;i++){
    if (i<3){
        newArray[i]=ordArray[i];
    }else if (i==3){
        newArray[i]=0;
    }else if (i>3){
        newArray[i]=ordArray[i-1];
    }
}
for (int x :newArray){
    System.out.println(x);
}