测试你自己的程序设计能力
自己写出string类的indexof方法？
static int indexOf2(char[] source, int sourceOffset, int sourceCount,char[] target, int targetOffset, int targetCount, int fromIndex) {char first = target[0];int max = sourceCount - targetCount;for (int i =0; i <= max; i++) {/* Look for first character. */if (source[i] != first) {while (++i <= max && source[i] != first);}/* Found first character, now look at the rest of v2 */if (i <= max) {int j = i + 1;int end = i + targetCount;for (int k = 1; j < end&& source[j] == target[k]; j++, k++);if (j == end) {/* Found whole string. */return i ;}}}return -1;}