值传递 函数传参的过程实际上是形式参数被实际参数赋值的过程; 值传递:形式参数修改不了实际参数; void swap1(int num1,int num2) { int temp; temp = num1; num1 = num2; num2 = temp; printf("num1 = %d\n",num1); printf("num2 = %d\n",num2); }