动态内存指针

Question

int main(int argc, char **argv) {
    float *rainfall;
    float rain_today;
    // rainfall has been dynamically allocated space for a floating point number.
    // Both rainfall and rain_today have been initialized in hidden code. 
    // Assign the amount in rain_today to the space rainfall points to.

    return 0;
}

大家好。这是一个非常基本的问题，但我还没有找到解决方案。 不仅仅是

rain_today = *rainfall

Answer 1

没有

rain_today = *rainfall;将获取rainfall指向的值并将其放入rain_today（理想情况下为NULL）。

要求您做的是将rain_today的值放入指针rainfall指向的空间

是：

*rainfall = rain_today \\the value of rain_toady is COPIED to the space pointed by rainfall

或者你可以这样做：

rainfall = &rain_today \\rainfall points at the memory location of rain_today