基本思想 将有序序列分成2部分，通过比较，决定查找元素在前半部分还是后半部分，然后递归。 代码
public class BinaryTest { public static int binary(int[] array, int value) { int low = 0; int high = array.length - 1; while(low <= high) { int middle = (low + high) / 2; if(value == array[middle]) { return middle; } if(value > array[middle]) { low = middle + 1; } if(value < array[middle]) { high = middle - 1; } } return -1; } public static void main(String[] args) { int[] a = {1, 2, 3, 4, 5, 6, 7, 8, 9}; int value = binary(a, 9); System.out.println(value); } }