为什么srand(time(NULL))中的NULL是什么意思？

[Snailqiu]

为什么对于time要传递一个NULL？

[赵4老师]

VS IDE中，在不明白的符号上点鼠标右键，选转到定义。

[querdaizhi]

引用 3 楼 max_min_ 的回复:

 time() returns the time since the Epoch (00:00:00 UTC, January 1, 1970), 
measured in seconds.
If t is non-NULL, the return value is also stored in the memory pointed to by t.

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[lpcads]

time(NULL)返回当前时间，用于随机数种子

[lpcads]

time这个函数由于历史问题，有两种用法 time(&t); //由t返回时间 或者 t=time(NULL);

[max_min_]

 time() returns the time since the Epoch (00:00:00 UTC, January 1, 1970), 
measured in seconds.
If t is non-NULL, the return value is also stored in the memory pointed to by t.