如果有一va函数的声明是void va_test(char a, char b, char c, …),则它的固定参数依次是a,b,c,最后一个固定参数argN为c,因此就是 va_start(arg_ptr, c)。 va_arg(arg_ptr, type):返回参数列表中指针arg_ptr所指的参数,返回类型为type,并使指针arg_ptr指向参数列表中下一个参数。 va_copy(dest,...
Variable Argument Functions项目 2013/03/11 Usually the functions defined in C/C++ take constant number of arguments which are decided while declaring the functions. Sometimes we do need the functions that can accept variable number of arguments, Printf() function is a great example of such ...
{ va_list arguments;doublesum =0;/*Initializing arguments to store all values after num*/va_start ( arguments, num );/*Sum all the inputs; we still rely on the function caller to tell us how many there are*/for(intx =0; x < num; x++) { sum+= va_arg ( arguments,double); ...
Output When the above code is compiled and executed, it produces the following output − Average of 2, 3, 4, 5 = 3.500000 Average of 5, 10, 15 = 10.000000 It should be noted that the functionaverage()has been called twice and each time the first argument represents the total number ...
从底层来看,inline的原理是编译时展开,如果允许调用va_xx的函数被内联,那么获取到的将是展开位置的变长参数列表(而且va_start和va_end事实上是宏而非函数),可能不符合预期行为。 GPT: 可变参数 (...) 的获取机制是基于底层 ABI 的。 va_start()、va_arg()、va_end()都依赖当前调用帧(调用栈上的位置、寄...
In the C Programming Language, the vprintf function writes a formatted string to the stdout stream using arg as the variable argument list.
The type of the argument. Returns The va_arg function returns the value of the argument. Required Header In the C Language, the required header for the va_arg function is: #include <stdarg.h> Applies To In the C Language, the va_arg function can be used in the following versions: ...
4. Using Const with Function Arguments In C++, the const keyword can be used with function arguments to indicate that a function does not modify the value of the argument. When a function argument is declared as const, it cannot be changed within the function. This helps to prevent unintenti...
However, to make sure that my algebra/math wasn't wrong I did a command window session where I ran the sub function and was able to see where v_diff was zero so I am pretty confident in that actual expressions within the sub function, just not...
In C++ how to pass uint16_t variable to the function with an argument unsigned int &? Learn 發現卡 產品文件 開發語言 主題 登入 關閉警示 我們不會再定期更新此內容。 如需此產品、服務、技術或 API 的支援資訊,請參閱Microsoft 產品生命週期。