所以scanf_s需要输入三个参数,本例子中比scanf多输入一个数组的大小。所以程序这样修改: intmain(void) { charfname[40]; charlname[40]; printf("Enter your first name: "); scanf_s("%s",fname,sizeof(fname)); printf("Enter your last name: "); scanf_s("%s",lname,sizeof(lname)); pr...