C语言 函数'time'的隐式声明[-Wimplicit-function-declaration]|
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/15458393/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
implicit declaration of function 'time' [-Wimplicit-function-declaration]|
提问by Chathura Dodamgoda
Whenever I try to use srandfunction I get this warning
每当我尝试使用srand函数时，我都会收到此警告
"implicit declaration of function 'time' [-Wimplicit-function-declaration]|"
and a windows error reportappears when running the compiled file,
I'm a novice to c programming, I found this on a text book, but it doesn't work for me.
和Windows错误报告显示，当运行编译的文件，
我是一个新手，C ++编程，我发现这对一本教科书，但它不会对我来说有效。
srand (time());
int x= (rand()%10) +1;
int y= (rand()%10) +1;
printf("\nx=%d,y=%d", x,y);
What do I need to correct this?
我需要做什么来纠正这个问题？
回答by Paul R
You need to make sure that you #includethe right headers, in this case:
#include在这种情况下，您需要确保正确的标题：
#include <stdlib.h> // rand(), srand()
#include <time.h> // time()
When in doubt, check the man pages:
如有疑问，请查看手册页：
One further problem: time()requires an argument, which can be NULL, so your call to srand()should be:
另一个问题：time()需要一个参数，可以是NULL，所以你的调用srand()应该是：
srand(time(NULL));
回答by Acsor
Note that time()function uses current time (expressed in seconds since 1970) both in its return value and in its address argument.
请注意，该time()函数在其返回值和地址参数中均使用当前时间（以 1970 年以来的秒数表示）。
