如何在C中将数组初始化为0 ?

I need a big null array in C as a global. Is there any way to do this besides typing out

我需要一个大的空数组作为全局变量。除了打字之外，还有什么别的办法吗

char ZEROARRAY[1024] = {0, 0, 0, /* ... 1021 more times... */ };

吗?

2 个解决方案

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Global variables and static variables are automatically initialized to zero. If you have simply

全局变量和静态变量被自动初始化为零。如果你有简单的

char ZEROARRAY[1024];

at global scope it will be all zeros at runtime. But actually there is a shorthand syntax if you had a local array. If an array is partially initialized, elements that are not initialized receive the value 0 of the appropriate type. You could write:

在全局范围内，在运行时将是所有的0。但是如果你有一个本地数组，实际上有一个简写语法。如果数组被部分初始化，则未初始化的元素将接收适当类型的值0。你可以写:

char ZEROARRAY[1024] = {0};

The compiler would fill the unwritten entries with zeros. Alternatively you could use memset to initialize the array at program startup:

编译器会用0填充未写的条目。也可以使用memset在程序启动时初始化数组:

memset(ZEROARRAY, 0, 1024);

That would be useful if you had changed it and wanted to reset it back to all zeros.

如果您更改了它并想将它重置为所有的0，那么这将非常有用。

If you'd like to initialize the array to values other than 0, with gcc you can do:

如果要将数组初始化为非0的值，可以使用gcc:

int array[1024] = { [ 0 ... 1023 ] = -1 };

This is a GNU extension of C99 Designated Initializers. In older GCC, you may need to use -std=gnu99 to compile your code.

这是C99指定初始化器的GNU扩展。在旧的GCC中，您可能需要使用-std=gnu99来编译代码。

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