iterator指针回到0_回到基础与指针
现在让我们瞄准指针 (Now Let’s the )
A is a , used to store the of .
The the of the first byte of a , as we know the size of a , the rest of the bytes are easy to .
指针存储变量的第一个字节的地址，因为我们知道变量的大小，其余字节很容易计算。
在C中声明指针 ( in C)
* is used to . The looks like this-
*符号用于声明指针。 声明看起来像这样-
int *p; and we like this — int v;
int *p; 并且我们这样声明变量— int v;
We can now say that p is a ‘ to int’, of the type int. It will store the of .
由于类型int ，我们现在可以说p是“指向int的指针” 。 它将存储整数变量的地址。
All the are of the same size they just store a , which does not for a . , data types .
所有指针的大小相同，因为它们仅存储一个内存地址，对于计算机而言，该地址不会更改。 但是，不同的数据类型需要不同的指针声明。
char * character;
double * number;
float * balance;This was just the . Right now they do not store any value. To do that, we must them with the of to store. In C, the & AKA ‘-of ’ is used to get the of a .
这只是宣言。 目前，它们不存储任何值。 为此，我们必须为他们提供另一个要存储的变量的地址。 在C语言中，“＆”符号& AKA“运算符的地址”用于获取变量的地址。
int a = 1000; // a stores the value 1000
int *p = &a; // p stores the memory address of a. NOT 1000
// Another Wayint a = 1000;
int *p;
p = &a; // Notice * is not used again. We only use it while declaring.取消引用指针 ( )
Once a is , the next step is to use it. We need to refer to the value it to, known as the of the . This is known as the . To do this, we use the *.
声明指针后，下一步就是使用它。 我们需要引用它指向的值，称为指针的目标。 这称为取消引用指针。 为此，我们使用符号* 。
int * ptr; // declaring a pointer to int
int a = 6; // a stores the value 6
ptr = &a; // p stores the memory address of a. NOT 6
printf("%d", *ptr); //prints 6. Astrix is used to dereference the pointer空指针 (Null )
A null is a with a value 0. 0 is the only value you can to a , will give an error. A null is a you can use to a later. Here’s how to set null —
空指针是值为0的特殊指针。0是可以分配给指针的唯一整数值，任意值都会产生错误。 空指针是一个占位符，以后可以用来初始化指针。 这是设置空指针的方法-
int *p = 0; //Works fine
int *z = 100; //Error
int a = 420;p = &a; //Works fine. Now P stores the address of a
