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一.arrays的工具类
1. arrays.sort 是对数组的排序(从小到大)
int a[] =
{1,3,5,2,9
};
Arrays.sort (a );
for ( int i : a) {
System.out.print(i);
}
Arrays.sort (a );
for ( int i : a) {
System.out.print(i);
}
2.Arrays.binarySerch 二分查找,找到则定位元素下标
int a[] = {1,3,5,2,9};Arrays.sort(a);
System.out.print(Arrays.binarySearch(a, 3));
3.Arrays.toString 数组的打印
int a[] = {1,3,5,2,9};String aString = Arrays.toString(a);//String前面的a代表数组,后面也是
System.out.println(aString);
4.Arrays.fill 数组的填充
int[] a = new int[3];Arrays.fill(a, 3);//将所有的都填充为3
System.out.println(Arrays.toString(a));
5.Arrays.equals 判断两个数组大小是否相等
int a[] = {1,3,4};int b[] = {2,4,8,9};
System.out.println(Arrays.equals(a, b));//结果则是两个数组大小不同
6.Arrays.asList(a) 查看数组中的特定值
int b[] = {2,4,8,9};System.out.println(Arrays.asList(b).contains(9));//结果只能为true或者false
7.Arrays.copyOf 数组的拷贝
int b[] = {2,4,8,9};Arrays.copyOf(b, 6);//6为数组的长度
System.out.println(Arrays.toString(b));