java数组基础

public static void main(String[] args) {

// TODO Auto-generated method stub

int[] ary5 = new int[3];

for(int i = 0;i < ary5.length;i++){

System.out.print("ary5[" + i + "] = " + ary5[i] + " ");

}

System.out.println();

ary5 = new int[]{2,3,44,5,4,3,34,34,2};

for(int i = 0;i < ary5.length;i++){

System.out.print("ary5[" + i + "] = " + ary5[i] + " ");

}

System.out.println();

int[] arry = ary5;

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

System.out.print("arry[" + i + "] = " + arry[i] + " ");

}

System.out.println();

//不建议使用的声明数组变量的方法

int ary8[]; //等价于int[] ary8 此做法是为了c语言习惯兼容

//数组变量的赋值

int[] ary10 = new int[3];

ary10[1] = 10;

int[] ary11 = new int[]{4,5,6,7};

for(int i = 0;i < ary11.length;i++){

System.out.print("ary11[" + i + "] = " + ary11[i] + " ");

}

System.out.println();

ary11 = ary10;

for(int i = 0;i < ary10.length;i++){

System.out.print("ary11[" + i + "] = " + ary11[i] + " ");

}

System.out.println();

//数组复制不能使用引用的方法，应使用下面方法

int[] ary12 = new int[ary11.length];

for(int i = 0 ; i < ary11.length;i++){

ary12[i] = ary11[i];

}

System.out.println(Arrays.toString(ary12));

//java5以后的 api提供的更加简洁的赋值方法

int[] arrarCopy = Arrays.copyOf(ary12,ary12.length);

System.out.println(Arrays.toString(arrarCopy));

System.out.println(arrarCopy.length);

//java API提供了“高效”数组对象赋值方法，采用c实现

int[] arrayCopy1 = new int[]{1,2,3,4,5};

int[] arrayCopy2 = new int[arrayCopy1.length];

System.arraycopy(arrayCopy1, 0, arrayCopy2, 0, arrayCopy1.length);

System.out.println(Arrays.toString(arrayCopy2));

//可以采用复制数组对象到新的数组中，新数组的长度超过原数组，用这种方式变通实现数组的容量改变

//类似音乐播放器的播放列表

int[] array1 = {6,7,8};

int[] temp = Arrays.copyOf(array1, array1.length + 1);

array1 = temp; //重新对array1赋值，这样就改变了器长度

array1[array1.length -1] = 9;

System.out.println(Arrays.toString(array1));

}