在C语言中,return null这样的表述是不正确的,因为C语言中不存在null这样的关键字或者直接作为返回值的类型,在C语言中,通常我们使用NULL宏来表示空指针,而且这个宏通常是在标准库的头文件中定义的,例如stdio.h或者stdlib.h中,如果尝试在函数中返回NULL,该函数的返回类型必须是指针类型。 (图片来源网络,侵删) 下面...
return 0; 一般0代表的是正常结束 1. return -1; -1代表非正常结束 1. return ; void 返回是空,void返回值可以什么也不写,可以写return; 1. return NULL; 如果数据类型是指针类型,那我们一般成功的时候返回相应的地址,失败的时候返回NULL 1. 关于NULL,我这就简单记成 描述地址时用NULL‘清零’,描述数据时...
#include<iostream>usingnamespacestd;classError{public:Error(constchar*str="未知错误"):_str(str){}constchar*what()const{return_str.c_str();}protected:string_str;};voidinsertArray(intarray[],int*curNum,intposData,intmaxLength){if(*curNum>=maxLength){throwError("数组下标溢出!");}array[*cu...
void* CAge::operatornew(size_tnSize){returnmalloc(nSize); }void* CAge::operatornew(size_tnSize, LPCSTR lpszFileName,intnLine){ UNREFERENCED_PARAMETER(lpszFileName); UNREFERENCED_PARAMETER(nLine);returnmalloc(nSize); } CObject::Serialize ...
container return rati container testing container truck container uniform lia container width containeror cartonsco container-address container-based containerd containerisable containeronflatcarcof containers closures n containers of metal f containerctnr containing errors or containing three part containing ...
common language code common language famil common line common lisp common lisp object sy common local optimiza common logic address commonly seen wirewor commonly used image p commonly used legal t commonly used system common machine langua common machine langua common management inf common management ...
将RECT 参数的 NULL 传递给 InvalidateRect Win32 函数。示例C++ 复制 //The following example attaches an HWND to the CWindow object and //calls CWindow::Invalidate() to invalidate the entire client area CWindow myWindow; myWindow.Attach(hWnd); myWindow.Invalidate(); ...
g_signal_connect (app, "activate", G_CALLBACK (activate), NULL); status = g_application_run (G_APPLICATION (app), argc, argv); g_object_unref (app); return status; } 如果直接弄到 Visual Studio Code 里面是跑不起来的, 总 ** 的报错。
char data[] = "{" "\"text\": \"我是一个字符串数据\"," "\"number\" : 666," "\"state1\" : false," "\"state2\" : true," "\"state3\" : null" "}"; int main() { //1. 载入JSON数据 cJSON* root = cJSON_Parse(data); if (root == NULL)return 0; //2. 解析字段...
XS是Perl与C的胶水语言,通过它能在Perl中创建方法,以此扩展C库中的函数或新定义的C函数,详情可参阅《官方手册:perlxs》。 XS的编译器叫做xsubpp,它用typemaps去决定如何映射C函数的参量和输出值到Perl的值中并返回。“XSUB结构(XSUB forms)”是XS接口的基本单元,一个XSUB被编译后等效于一个C函数,其转化过程...