Arrays类对数组的操作

本篇文章仅提供一下常用对数组操作的方法及案例：

Arrays.equals(array1, array2);

Arrays.sort(array);
Arrays.fill(array, val);
Arrays.toString(array);
Arrays.copyOf(array, newLength);

Arrays.binarySearch(array, val);

/**
* Arrays.equals(array1, array2);
* 比较两个数组是否相同，必须是元素的个数和对应元素的大小一一相同才返回true
* 支持八种基本数据类型的比较
*/
String[] name1 = new String[]{"iPhone4","iPhone4S","iPhone5","iPhone5S"};
String[] name2 = {"iPhone4","iPhone4S","iPhone5","iPhone5S发烧"};

System.out.println(Arrays.equals(name1, name2));//false

/**
* Arrays.sort(array);
* 对数组按照从小到大排序
* 数据类型可以是：byte short char int long float double object对象
*/
int[] sum = new int[]{45,85,65,20,10,6};
Arrays.sort(sum);
for (int i = 0; i < sum.length; i++) {
System.out.print(sum[i]+" ");
}
System.out.println();
/**
* Arrays.fill(array, val);
* 把数组的元素值全部替换为val
* 支持八种基本数据类型的替换
*/
char[] c = new char[]{'Z','Y','C','D','A'};
for (int i = 0; i < c.length; i++) {
System.out.print(c[i]+" ");
}
System.out.println();
Arrays.fill(c, 'M');
for (int i = 0; i < c.length; i++) {
System.out.print(c[i]+" ");
}
System.out.println();
/**
* Arrays.toString(array);
* 把数组转化为String字符串
* 支持八种基本数据类型的转化
*/
String[] str = new String[]{"刘德华","范冰冰","王宝强","黄渤"};
int[] count = new int[]{45,85,49,51,21};
System.out.println(Arrays.toString(str));
// System.out.println(Arrays.toString(count));

/**
* Arrays.copyOf(array, newLength);
* copy一个长度为newLength的新数组  ①如果比原数组长度短，则是截取原数组；
* ②如果比原数组长，新增加的位置用默认值补充
*/
System.out.println(Arrays.toString(Arrays.copyOf(count, 10)));

/**
* Arrays.binarySearch(array, val)
* 查询数组array里面val元素的下标
*/
Arrays.sort(count);
for (int i = 0; i < count.length; i++) {
System.out.print(count[i]+" ");
}
System.out.println();
System.out.println(Arrays.binarySearch(count, 90));