# C 编程中的指针和数组 > 原文： [https://beginnersbook.com/2014/01/c-pointer-to-array-example/](https://beginnersbook.com/2014/01/c-pointer-to-array-example/) 在本指南中，我们将学习如何在 C 程序中使用指针和数组。我建议你在阅读本指南之前参考[数组](https://beginnersbook.com/2014/01/c-arrays-example/)和[指针](https://beginnersbook.com/2014/01/c-pointers/)教程，这样你就可以很容易地理解这里解释的概念了。 ## 打印数组元素地址的简单示例 ```c #include <stdio.h> int main( ) { int val[7] = { 11, 22, 33, 44, 55, 66, 77 } ; /* for loop to print value and address of each element of array*/ for ( int i = 0 ; i < 7 ; i++ ) { /* The correct way of displaying the address would be using %p format * specifier like this: * printf("val[%d]: value is %d and address is %p\n", i, val[i], &val[i]); * Just to demonstrate that the array elements are stored in contiguous * locations, I m displaying the addresses in integer */ printf("val[%d]: value is %d and address is %d\n", i, val[i], &val[i]); } return 0; } ``` **输出：** ```c val[0]: value is 11 and address is 1423453232 val[1]: value is 22 and address is 1423453236 val[2]: value is 33 and address is 1423453240 val[3]: value is 44 and address is 1423453244 val[4]: value is 55 and address is 1423453248 val[5]: value is 66 and address is 1423453252 val[6]: value is 77 and address is 1423453256 ``` > 请注意，每个元素之间存在 4 个字节的差异，因为这是整数的大小。这意味着所有元素都存储在内存中的连续位置。（参见下图）  在上面的例子中，我使用`&val[i]`来获取数组的第`i`个元素的地址。我们也可以使用指针变量而不是使用`&`符号来获取地址。 ## 示例 - C 中的数组和指针示例 ```c #include <stdio.h> int main( ) { /*Pointer variable*/ int *p; /*Array declaration*/ int val[7] = { 11, 22, 33, 44, 55, 66, 77 } ; /* Assigning the address of val[0] the pointer * You can also write like this: * p = var; * because array name represents the address of the first element */ p = &val[0]; for ( int i = 0 ; i<7 ; i++ ) { printf("val[%d]: value is %d and address is %p\n", i, *p, p); /* Incrementing the pointer so that it points to next element * on every increment. */ p++; } return 0; } ``` 输出： ```c val[0]: value is 11 and address is 0x7fff51472c30 val[1]: value is 22 and address is 0x7fff51472c34 val[2]: value is 33 and address is 0x7fff51472c38 val[3]: value is 44 and address is 0x7fff51472c3c val[4]: value is 55 and address is 0x7fff51472c40 val[5]: value is 66 and address is 0x7fff51472c44 val[6]: value is 77 and address is 0x7fff51472c48 ``` **注意事项：** 1）使用数组和指针时，指针的数据类型必须与数组的数据类型匹配。 2）你也可以使用数组名来初始化指针，如下所示： ```c p = var; ``` 因为数组名称本身就等于数组的基址。 ```c val==&val[0]; ``` 3）在循环中，对指针变量执行递增操作（`p++`）以获取下一个位置（下一个元素的位置），此算法对于所有类型的数组都是相同的（对于所有数据类型`double`，`char`，`int`等）即使每种数据类型消耗的字节不同。 **指针逻辑** 你必须已经理解了上面代码中的逻辑，所以现在是时候玩几个指针算术和表达式了。 ```c if p = &val[0] which means *p ==val[0] (p+1) == &val[2]  & *(p+1) == val[2] (p+2) == &val[3]  & *(p+2) == val[3] (p+n) == &val[n+1) & *(p+n) == val[n+1] ``` 使用这个逻辑，我们可以用更好的方式重写我们的代码： ```c #include <stdio.h> int main( ) { int *p; int val[7] = { 11, 22, 33, 44, 55, 66, 77 } ; p = val; for ( int i = 0 ; i<7 ; i++ ) { printf("val[%d]: value is %d and address is %p\n", i, *(p+i), (p+i)); } return 0; } ``` 我们在这个程序中不需要`p++`语句。