使用指针初始化字符串

Question

What is the difference between:

char arr[20]="I am a string"

and

char *arr="I am a string"

How is it possible to initialize an array just by using a pointer?

Answer 1

第一个很清楚，它是一个数组初始化，而第二个意味着字符指针* arr指向未命名的静态数组，该数组将存储字符串“ I is a string”。

Answer 2

One difference is in allocated storage size. First expression allocates 20 chars, but the second expression allocate the length of the string (13 chars).

The second difference is mentioned in this post . which is discussed on the way how these variables are allocated.

Answer 3

In first case you are partially initializing stack allocated array with 14 chars taken from buffer represented by "I am a string" string literal.

In second case you are initializing stack allocated pointer with a pointer to a buffer with static storage duration represented by "I am a string" string literal. Also notice that in second case you should use const char *arr .